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Found 1559 calculators
Trip average speed
Calculates average speed from distance in kilometers and time in hours.
Trip time from distance and speed
Calculates trip time from distance in kilometers and average speed in km/h.
Trip distance from speed and time
Calculates trip distance from speed in km/h and time in hours.
Fuel consumption L/100 km
Calculates average fuel consumption in L/100 km from fuel used and distance.
Fuel range from tank and consumption
Estimates range in kilometers from fuel amount in liters and L/100 km consumption.
Trip fuel cost
Calculates trip fuel cost from distance, L/100 km consumption, and price per liter.
Cost per 100 km
Calculates fuel cost per 100 km from L/100 km consumption and price per liter.
Simplified CO2 emission from fuel
Simplified CO2 emissions calculator: the result depends on fuel used and the selected emission factor in kg/L.
Engine displacement calculator
Calculates engine displacement from bore, stroke and cylinder count.
Mean piston speed
Calculates mean piston speed from engine stroke and rotational speed.
Stroke from mean piston speed
Solves engine stroke from mean piston speed and rotational speed.
Engine compression ratio
Calculates geometric compression ratio from total cylinder volume and clearance volume.
Engine clearance volume
Solves clearance volume from cylinder swept volume and compression ratio.
BMEP from torque
Calculates brake mean effective pressure from torque and engine displacement for a four-stroke model.
Torque from BMEP
Solves torque from BMEP and engine displacement for a simplified four-stroke model.
Power from BMEP, displacement, and speed
Calculates power from BMEP, displacement, and rotational speed for a simplified four-stroke engine.
Air flow from displacement and volumetric efficiency
Estimates theoretical intake air volume flow from engine displacement, speed, and volumetric efficiency.
Engine volumetric efficiency
Solves volumetric efficiency from actual air flow, displacement, and rotational speed.
Fuel mass flow from power and BSFC
Calculates fuel mass flow from power and brake-specific fuel consumption.
BSFC from power and fuel flow
Solves brake-specific fuel consumption from power and fuel mass flow.
Wheel torque from engine torque
Calculates wheel torque from engine torque, total ratio, and drivetrain efficiency.
Engine torque from wheel torque
Solves required engine torque from wheel torque, total ratio, and drivetrain efficiency.
Tractive force from wheel torque
Calculates tire contact tractive force from wheel torque and rolling radius.
Tractive force from engine torque
Calculates tractive force from engine torque, total ratio, drivetrain efficiency, and rolling radius.
Vehicle speed from engine speed
Calculates vehicle speed from engine rotational speed, total ratio, and wheel rolling radius.
Engine speed from vehicle speed
Calculates engine rotational speed from vehicle speed, total ratio, and rolling radius.
Drivetrain total ratio
Calculates total drivetrain ratio from gear ratio and final drive ratio.
Wheel power from engine power
Calculates wheel power from engine power and drivetrain efficiency.
Drivetrain efficiency
Solves drivetrain efficiency from input and output power.
Acceleration from tractive force
Calculates vehicle acceleration from tractive force, resistance force, and vehicle mass.
Grade force
Calculates the force needed to overcome a grade from vehicle mass and slope angle.
Maximum grade angle from tractive force
Estimates maximum grade angle from available tractive force and vehicle mass.
Gear speed per 1000 rpm
Calculates km/h per 1000 engine rpm from wheel circumference and ratios.
Gear ratio from teeth
Calculates a gear pair ratio from the drive and driven tooth counts.
Gearbox output speed
Calculates output rotational speed from input speed and ratio.
Gearbox output torque
Calculates output torque from input torque, ratio, and efficiency.
Gearbox input torque
Solves required input torque from output torque, ratio, and efficiency.
Gearbox power loss
Calculates gearbox power loss from input power and efficiency.
Gearbox total ratio
Calculates total ratio from gear ratio and final drive ratio.
Vehicle speed in gear
Calculates vehicle speed from engine speed, total ratio, and wheel rolling radius.
Engine speed at vehicle speed
Calculates engine speed for a given vehicle speed, total ratio, and rolling radius.
RPM drop after gear shift
Estimates engine speed after a shift and the speed drop from the new and old gear ratios.
Gear ratio step
Calculates the percentage step between a new and old gear ratio.
Required ratio for target speed
Solves the required total ratio for a target vehicle speed, engine speed, and rolling radius.
Simple gearbox output torque
Calculates simplified gearbox output torque as engine torque times ratio and efficiency.
Clutch torque capacity
Calculates simplified clutch torque capacity from clamp force, friction coefficient, mean radius, and number of active friction interfaces.
Required clutch clamp force
Solves required clamp force for a target torque, friction coefficient, mean radius, and friction surface count.
Required clutch friction coefficient
Solves required friction coefficient for a target torque, clamp force, mean radius, and friction surface count.
Required number of active clutch friction interfaces
Solves the exact and minimum integer number of active friction interfaces required to transmit a target torque.
Mean clutch friction radius
Calculates effective clutch friction radius for the uniform wear or uniform pressure assumption.
Clutch torque from inner and outer radius
Calculates simplified clutch torque from ring radii for the uniform wear or uniform pressure model.
Clutch slip power
Calculates power dissipated during clutch slip from torque and angular speed difference.
Clutch slip energy
Calculates energy dissipated during slip from slip power and time.
Clutch slip time
Solves slip time from dissipated energy and slip power.
Clutch safety factor
Calculates safety factor from clutch torque capacity and engine torque.
Required clutch torque capacity
Solves required clutch torque capacity from engine torque and safety factor.
Average clutch friction-surface pressure
Calculates average friction-surface pressure from clamp force and friction ring area; it is not maximum pressure or a pressure distribution.
Clutch friction ring area
Calculates friction ring area from outer and inner radius.
Speed from skid marks
Estimates initial speed from skid-mark length, friction, final speed, and road grade.
Braking distance from speed and grade
Solves braking distance for locked wheels from initial speed, final speed, friction, and road grade.
Speed from multiple braking segments
Estimates initial speed from v0^2 = vf^2 + 2 * sum(a_i d_i) for segments with different friction and grades.
Braking force from braking torque
Calculates braking force at the wheel from braking torque and wheel radius.
Braking torque from braking force
Calculates braking torque from wheel braking force and wheel radius.
Braking deceleration from force and mass
Calculates theoretical braking deceleration from total braking force and vehicle mass.
Braking distance from speed and deceleration
Calculates braking distance for constant deceleration and initial speed.
Braking time from speed and deceleration
Calculates braking time for constant deceleration and initial speed.
Kinetic energy to dissipate during braking
Calculates vehicle kinetic energy that the brake system must dissipate.
Braking thermal power from energy and time
Calculates average thermal power dissipated during braking.
Brake friction force from normal force and friction coefficient
Calculates friction force from normal force and friction coefficient.
Brake friction torque from friction force and effective radius
Calculates brake friction torque from friction force and effective radius.
Front/rear braking force distribution
Splits total braking force between front and rear axles by a specified front share.
Brake thermal energy
Calculates energy to dissipate when braking from initial to final speed.
Tire overall diameter
Calculates tire overall diameter from width, aspect ratio, and rim diameter.
Rolling radius from tire diameter
Estimates rolling radius as half of the supplied tire diameter.
Wheel circumference from diameter
Calculates wheel circumference from the supplied tire diameter.
Wheel revolutions per kilometer
Calculates the number of wheel revolutions required to travel one kilometer.
Vehicle speed from wheel RPM
Calculates vehicle speed from wheel rotational speed and tire diameter.
Wheel RPM from vehicle speed
Calculates wheel rotational speed from vehicle speed and tire diameter.
Tire diameter difference
Compares a new tire diameter with a reference diameter in absolute and percentage terms.
Speedometer error from tire change
Estimates actual speed and indicated-speed error after tire diameter change.
Ride height change from tire diameter
Calculates ride height change as half of the diameter difference between new and reference tires.
Tire contact force from wheel torque
Calculates tangential tire contact force from wheel torque and rolling radius.
Wheel torque from tire force
Solves required wheel torque from tire contact force and rolling radius.
Wheel load from vehicle mass distribution
Calculates static load on one wheel from vehicle mass and the load share of the analyzed axle.
Tire circumference
Calculates circumference from a supplied diameter.
Speedometer error from tire circumference
Estimates percentage speedometer error after tire circumference change.
Spring deflection from force and rate
Calculates linear spring deflection from applied force and spring rate.
Spring force from deflection and rate
Calculates linear spring force from deflection and spring rate.
Wheel rate from spring rate
Calculates wheel rate from spring rate and motion ratio.
Spring rate from wheel rate
Solves required spring rate from wheel rate and motion ratio.
Suspension natural frequency
Calculates undamped natural frequency from sprung mass and wheel rate.
Wheel rate from natural frequency
Solves wheel rate from target natural frequency and sprung mass.
Suspension static sag
Calculates static sag from corner mass and wheel rate.
Required spring rate for static sag
Solves required spring rate for corner mass, target static sag, and motion ratio.
Suspension critical damping
Calculates linear critical damping coefficient from sprung mass and wheel rate.
Damping coefficient from damping ratio
Calculates actual linear damping coefficient from damping ratio, sprung mass, and wheel rate.
Damping ratio from damping coefficient
Solves damping ratio from actual damping coefficient, sprung mass, and wheel rate.
Longitudinal load transfer
Calculates longitudinal load transfer during braking or acceleration from mass, acceleration, center of gravity height, and wheelbase.
Turning radius from wheelbase and steer angle
Calculates turning radius from wheelbase and road wheel steer angle.
Road wheel angle from turning radius
Solves road wheel angle from turning radius and wheelbase.
Turning diameter from turning radius
Calculates turning diameter as twice the turning radius.
Ackermann inner angle
Solves the Ackermann inner angle from outer angle, wheelbase, and track width.
Ackermann outer angle
Solves the Ackermann outer angle from inner angle, wheelbase, and track width.
Ideal Ackermann angle difference
Calculates the difference between inner and outer Ackermann angles.
Steering ratio
Calculates steering ratio from steering wheel angle and road wheel angle.
Road wheel angle from steering wheel angle
Calculates road wheel angle from steering wheel angle and steering ratio.
Steering wheel angle required
Solves the steering wheel angle required for a target road wheel angle and steering ratio.
Vehicle arc length
Calculates arc length from radius and sweep angle.
Lateral acceleration from steer angle
Calculates lateral acceleration from road wheel steer angle, wheelbase, and speed.
Minimum turning radius
Calculates minimum turning radius from maximum road wheel steer angle and wheelbase.
Vehicle acceleration from net force
Calculates vehicle acceleration from net force and vehicle mass.
Net force for vehicle acceleration
Solves the net force needed to achieve a target vehicle acceleration.
Vehicle rolling resistance
Calculates rolling resistance from vehicle mass and rolling resistance coefficient.
Vehicle aerodynamic drag
Calculates aerodynamic drag from speed, Cd, frontal area, and air density.
Aerodynamic drag power
Calculates the power needed to overcome aerodynamic drag at a given speed.
Total vehicle road load
Sums rolling resistance, aerodynamic drag, and grade resistance into total road load.
Wheel power for constant speed
Calculates wheel power needed to hold constant speed for a known total road load.
Lateral acceleration in a corner
Calculates lateral acceleration in a corner from speed and radius.
Corner radius from lateral acceleration
Solves corner radius from speed and lateral acceleration.
Vehicle lateral force
Calculates lateral force on the vehicle from mass and lateral acceleration.
Required friction for cornering
Estimates the minimum friction coefficient required for a given lateral acceleration.
Vehicle acceleration distance
Calculates acceleration distance from initial speed, final speed, and constant acceleration.
Empirical quarter-mile estimate
Estimates quarter-mile ET and trap speed from vehicle mass and power using common W_lb/P_hp formulas.
Power-to-mass ratio
Converts vehicle power and mass into hp/t, kW/t, and kg/kW.
Fuel consumption from volume and distance
Calculates average fuel consumption as fuel volume divided by distance.
Fuel volume from consumption and distance
Solves fuel volume used from distance and average fuel consumption.
Range from fuel volume and consumption
Estimates range from available fuel volume and average fuel consumption.
Trip fuel cost
Calculates trip fuel cost from distance, consumption, and fuel price per m3.
Fuel cost per 100 km
Calculates fuel cost per 100 km from average consumption and fuel price.
CO2 from fuel volume
Calculates CO2 mass from fuel volume and an emission factor in kg/m3.
CO2 per distance
Calculates CO2 emissions per unit distance and presents the result in the natural g/km unit.
Fuel mass flow from power and BSFC
Calculates fuel mass flow from power and brake-specific fuel consumption.
Fuel volume flow from power, BSFC and density
Calculates fuel volume flow from power, BSFC, and fuel density.
Average speed from distance and time
Calculates average speed from distance and travel time.
Travel time from distance and average speed
Calculates travel time from distance and average speed.
Monthly fuel cost
Calculates monthly fuel cost from monthly distance, consumption, and fuel price per m3.
EV energy consumption
Calculates auxiliary EV energy consumption in kWh/100 km.
EV range
Estimates EV range from usable battery energy and kWh/km consumption.
Fuel range
Estimates range from fuel volume in liters and L/100 km consumption.
Trip cost
Calculates trip cost from distance, consumption per 100 km, and unit price.
Heat power from coolant flow
Calculates cooling heat power from mass flow, specific heat, and temperature difference.
Required coolant flow
Solves required coolant mass flow for a target heat power and temperature difference.
Coolant temperature difference
Calculates coolant temperature difference from heat power, flow, and specific heat.
Heat energy absorbed by coolant
Calculates heat energy absorbed by coolant from mass, specific heat, and temperature difference.
Coolant heating time
Calculates coolant heating time from mass, specific heat, temperature difference, and heat power.
Heater power from air flow
Calculates heater power from air mass flow, specific heat, and temperature difference.
Required heater air flow
Solves required air mass flow for a target heater power.
Radiator air-side heat power
Calculates heat power rejected to air by the radiator from air flow and temperature difference.
Coolant mass from volume and density
Calculates coolant mass from volume and density.
Coolant concentrate and water volumes
Calculates concentrate and water volumes for a target mixture volume and concentrate ratio.
Mixed temperature of two fluids
Calculates mixed temperature of two fluids from masses, specific heats, and initial temperatures.
Temperature drop at constant cooling power
Calculates simplified temperature drop over time at constant cooling power.
Load current from power and voltage
Calculates load current from power and system voltage.
Load power from voltage and current
Calculates load power from voltage and current.
Battery runtime from capacity and current
Estimates load runtime from battery capacity and load current.
Battery used capacity
Calculates battery charge used from current and time.
Battery energy from voltage and capacity
Calculates battery energy from voltage and capacity expressed as electric charge.
Required alternator current
Sums load current and battery charging current as required alternator current.
Automotive wire voltage drop
Calculates wire voltage drop from current, loop length, cross-section, and resistivity.
Automotive wire power loss
Calculates wire power loss from current and wire resistance.
Automotive required wire cross-section
Solves minimum wire cross-section for an allowed voltage drop.
Automotive wire resistance
Calculates wire resistance from loop length, cross-section, and material resistivity.
Fuse current with margin
Calculates fuse current from operating current and a safety margin.
Battery runtime from load power
Calculates runtime from battery energy and load power.
EV AC charging time
Estimates AC charging time from energy to charge and charging power.
Accessory battery runtime
Calculates accessory runtime from battery energy in Wh and load power.
Required alternator power
Calculates power from system voltage and current.
Cylinder compression measurement deviation
Compares two compression measurement results and returns their relative difference; it does not determine the cause of the difference.
Battery voltage drop under load
Calculates the difference between open-circuit and loaded voltage without automatically assessing battery condition.
Alternator charging voltage deviation
Compares measured charging voltage with a provided reference voltage without assessing the cause of the deviation.
Ideal runtime under parasitic drain
Estimates ideal runtime from battery capacity and drain current without accounting for operating conditions.
Combined STFT and LTFT fuel trim
Adds short-term and long-term fuel trim; the result is not interpreted as a specific fault.
Wheel speed deviation
Compares measured speed with a reference speed and returns the absolute percentage deviation.
Sensor signal as percent of range
Converts a signal relative to the provided minimum and maximum; out-of-range values are allowed for erroneous-signal analysis.
Coolant warmup rate
Calculates average coolant temperature change rate in K/min from two temperatures and elapsed time.
Oil change interval remaining
Calculates remaining distance to an oil change from the interval and distance since the last change.
Service cost from parts and labor
Calculates total service cost from parts cost, labor hours, and hourly rate.
Tire wear difference
Calculates tread depth difference between two tires or measurements.
Brake pad wear rate
Calculates brake pad wear rate as millimeters per kilometer.
Coolant mixture ratio
Calculates concentrate and water volume from total volume and concentrate percentage.
Washer fluid dilution
Calculates concentrate and water volume for a target washer fluid concentration.
Maintenance cost per km
Calculates maintenance cost per kilometer from total maintenance cost and distance.
Annual vehicle cost
Sums annual fuel, insurance, maintenance, tax, and other costs.
Total vehicle cost per km
Calculates total vehicle cost per kilometer as an auxiliary ownership metric.
Bolt torque from clamp force
Estimates tightening torque from clamp force, bolt diameter, and nut factor K.
Bolt clamp force from torque
Estimates bolt clamp force from tightening torque, diameter, and nut factor K.
Bolt elongation
Calculates elastic bolt elongation from force, length, tensile area, and Young's modulus.
Bolt stress from force and area
Calculates bolt stress as force divided by tensile area.
Fluid dilution ratio
Calculates the component volume share in total mixture volume.
Weighted oil mixture value
Calculates a simplified volume-weighted average for two values, such as viscosity grade numbers.
Concentrate mixture volume
Calculates concentrate and water volume from total mixture volume and concentrate ratio.
Tire pressure temperature correction
Estimates tire pressure after a temperature change using a simplified ideal gas relation.
Tire pressure change from temperature
Calculates final pressure and pressure difference after a temperature change.
Fluid top-up volume
Calculates top-up volume from initial and target fluid volume.
Service cost
Calculates service cost from parts cost, labor rate per second, and labor time.
Remaining service interval
Calculates remaining distance to service from interval distance and distance since last service.
Power from torque
Calculates power from torque and rotational speed.
Electric charge from current and time
Calculates electric charge from current and time.
Current from charge and time
Calculates current from electric charge and time.
Time from charge and current
Calculates time from electric charge and current.
Conductance from resistance
Calculates conductance as the reciprocal of resistance.
Resistance from conductance
Calculates resistance as the reciprocal of conductance.
LED resistor calculator
Calculates resistance and resistor power for an LED current limiting resistor.
LED series resistor
Calculates a current limiting resistor for multiple LEDs connected in series.
LED resistor power
Calculates power dissipated in an LED current limiting resistor.
Zener resistor
Calculates the series resistor for a simple Zener diode regulator.
BJT base resistor
Calculates a base resistor for simplified BJT transistor drive.
Bridge rectifier average output
Estimates average voltage of an unloaded full-wave waveform without a smoothing capacitor.
Rectifier smoothing capacitor
Calculates ripple for a selected capacitance or required capacitance for an allowed ripple.
Diode conduction power loss
Calculates diode power loss from constant forward voltage and average current or conduction current with duty cycle.
BJT voltage divider bias
Calculates a simplified BJT operating point from base divider, emitter resistor and collector resistor.
MOSFET external gate resistor
Estimates required external gate resistance from gate charge and switching time.
MOSFET conduction loss
Calculates conduction loss from RMS current, Rds(on) and duty cycle.
MOSFET switching loss
Estimates MOSFET dynamic losses from voltage, current, switching times, frequency and gate-drive power.
Semiconductor junction temperature
Calculates junction temperature from ambient or case temperature with known power loss and thermal resistance.
Inverting op-amp gain
Calculates voltage gain of an ideal inverting operational amplifier.
Non-inverting op-amp gain
Calculates voltage gain of an ideal non-inverting operational amplifier.
RC low-pass cutoff
Calculates cutoff frequency of a simple RC low-pass filter.
RC high-pass cutoff
Calculates cutoff frequency of a simple RC high-pass filter.
PWM average voltage
Calculates PWM average voltage for duty cycle in the 0..1 range.
ADC resolution
Calculates ADC voltage step from reference voltage and bit count.
ADC code from voltage
Calculates ideal ADC code from input voltage, reference voltage and bit count.
Resistor voltage divider
Calculates output voltage of an ideal two-resistor divider.
Loaded voltage divider
Calculates output voltage of a resistor divider with load resistance in parallel with the lower resistor.
Current divider for two resistors
Calculates branch currents in an ideal two-resistor current divider.
Op-amp inverting gain
Calculates gain and output voltage of an ideal inverting op-amp.
Op-amp non-inverting gain
Calculates gain and output voltage of an ideal non-inverting op-amp.
Three-input op-amp summing amplifier
Calculates output voltage of an ideal inverting summing amplifier with three input resistors.
Matched-ratio op-amp differential amplifier
Calculates differential amplifier output for matched resistor ratios.
Op-amp integrator for constant input
Calculates output change and final voltage of an ideal integrator for a constant input voltage.
Op-amp differentiator for linear ramp
Calculates ideal op-amp differentiator output for a constant input voltage slope.
Op-amp maximum frequency from slew rate
Estimates maximum sine frequency from slew rate and peak output voltage.
Op-amp closed-loop bandwidth
Estimates closed-loop bandwidth from gain-bandwidth product and gain magnitude.
Duty cycle from on-time
Calculates PWM duty cycle and frequency from on-time and period.
Resistor power dissipation
Calculates power dissipated in a resistor from voltage and resistance.
Basic RL time constant
Calculates the time constant of a simple RL circuit from inductance and resistance.
PCB trace resistance
Calculates resistance of a simple PCB trace from resistivity, length, width and copper thickness.
PCB trace width and current
Estimates required width or approximate current of a PCB trace with an older simplified empirical model.
Logic gate
Calculates the output of a NOT, AND, OR, NAND, NOR, XOR, or XNOR gate for boolean/0/1 values.
Truth table up to 3 inputs
Generates a truth table for the selected gate and 1-3 inputs without an expression parser.
First-order RC filter
Solves f_c = 1/(2*pi*R*C) for a simple first-order RC filter.
1st-order crossover LP: series inductor
Sizes the series inductor for a first-order low-pass speaker crossover with resistive load R.
1st-order crossover HP: series capacitor
Sizes the series capacitor for a first-order high-pass speaker crossover with resistive load R.
2nd-order Butterworth low-pass crossover
Sizes the ideal LP topology: series inductor and shunt capacitor terminated by R.
2nd-order Butterworth high-pass crossover
Sizes the dual HP topology: series capacitor and shunt inductor terminated by R.
RC cutoff frequency
Calculates cutoff frequency of a simple RC filter.
RL cutoff frequency
Calculates cutoff frequency of a simple RL filter.
RL low-pass cutoff
Calculates cutoff frequency of a simple ideal RL low-pass filter.
LC resonant frequency
Calculates resonant frequency of an ideal LC circuit.
Ohm's law voltage
Calculates voltage from current and resistance in a DC circuit.
Ohm's law current
Calculates current from voltage and resistance in a DC circuit.
Ohm's law resistance
Calculates resistance from voltage and current in a DC circuit.
DC electrical power
Calculates DC electrical power from voltage and current.
DC power from current and resistance
Calculates DC power from current and resistance.
DC power from voltage and resistance
Calculates DC power from voltage and resistance.
Electrical demand power
Calculates demand power from total installed active power and a manually supplied demand factor. Energy demand in kWh additionally requires operating time and is a separate calculation.
Single-phase power
Calculates single-phase active power from voltage, current and power factor.
Reactive power from S and P
Calculates reactive power from apparent and active power.
Power factor from kW and kVA
Calculates power factor as active power divided by apparent power.
Electrical energy consumption estimate
Estimates daily and annual site electricity consumption from installed power, average utilization, operating hours per day, and operating days per year.
Electrical energy from power and time
Calculates electrical energy from power and operating time.
Energy cost
Calculates energy cost from energy amount and price per kWh.
Joule heating
Calculates energy dissipated in resistance from current and time.
Resistors in series
Calculates the total resistance of resistors connected in series.
Resistors in parallel
Calculates the total resistance of resistors connected in parallel.
Wire resistance
Calculates theoretical wire resistance from resistivity, length and cross-sectional area.
Resistance temperature coefficient
Calculates resistance after a temperature change using a linear temperature coefficient.
Conductivity from resistivity
Calculates electrical conductivity as the reciprocal of resistivity.
Resistor current limit from power
Calculates maximum current from resistor power rating and resistance.
Resistor voltage limit from power
Calculates maximum voltage from resistor power rating and resistance.
Preferred E-series resistor
Selects the nearest E12, E24, E48 or E96 resistor value.
Resistor color code
Decodes 4-, 5- and 6-band resistors.
Rectifier and ripple
Estimates rectifier voltage and ripple with a filter capacitor.
Voltage divider
Calculates the output voltage of an ideal resistor divider.
RC time constant
Calculates the time constant of a simple resistor-capacitor circuit.
DC current divider for two branches
Calculates currents in two parallel resistive branches of an ideal current divider.
Unknown branch current from KCL
Calculates signed unknown branch current from current balance; a negative result means the opposite direction to the assumption.
Unknown voltage from KVL
Calculates signed unknown voltage from a loop balance using the supplied source/drop convention.
DC source loaded voltage
Calculates DC source terminal voltage from source voltage, current, and internal resistance.
DC source internal power loss
Calculates power loss in a source internal resistance from current and resistance.
Power ratio and dB
Converts a positive power ratio and decibels.
Voltage ratio and dB
Converts voltage ratio to dB for equal impedances.
dBm and dBW power levels
Converts watts and dBm/dBW power levels.
dBm and dBW converter
Converts dBm and dBW power levels.
555 astable timer
Calculates ideal 555 astable oscillator parameters.
555 monostable timer
Calculates the pulse time of an ideal 555 monostable circuit.
Complex number: rectangular to polar
Converts real and imaginary parts to magnitude and phase.
Complex number: polar to rectangular
Converts magnitude and phase to real and imaginary parts.
Two complex impedances in series
Adds two impedances written as R + jX and returns real part, imaginary part, magnitude, and phase.
Two complex impedances in parallel
Combines two impedances written as R + jX in parallel and reports a zero-denominator error.
Period from frequency
Calculates waveform period from frequency.
Angular frequency
Calculates angular frequency from frequency.
RMS from peak
Calculates sinusoidal RMS voltage from peak voltage.
Peak from RMS
Calculates sinusoidal peak voltage from RMS voltage.
Capacitive reactance
Calculates capacitor reactance magnitude at a given frequency.
Inductive reactance
Calculates inductor reactance at a given frequency.
RC impedance magnitude
Calculates impedance magnitude of a series RC model.
RL impedance magnitude
Calculates impedance magnitude of a series RL model.
Series RLC impedance magnitude
Calculates impedance magnitude of a series RLC model.
Series RLC bandwidth and quality
Calculates resonant angular frequency and frequency, bandwidth, Q factor, and damping ratio.
Series RLC half-power frequencies
Calculates lower and upper half-power frequencies and bandwidth of an ideal series RLC circuit.
Series RLC quality factor
Calculates Q factor of an ideal series RLC circuit from inductance, capacitance and resistance.
LC resonant frequency
Calculates resonant frequency of an ideal LC circuit.
Parallel RLC branch currents
Calculates R, L, and C branch currents, reactive component, total current, phase, and power factor.
Power factor from phase angle
Calculates power factor as cosine of phase angle.
Single-phase apparent power
Calculates single-phase apparent power from RMS voltage and RMS current.
Single-phase active power
Calculates single-phase active power from RMS voltage, RMS current and power factor.
Single-phase reactive power
Calculates single-phase reactive power from RMS voltage, RMS current and phase angle.
Parallel RLC circuit
Calculates admittance, impedance, branch currents and resonance of a simple parallel RLC circuit.
Wheatstone bridge
Calculates bridge output voltage and an unknown resistance at balance.
Capacitor energy
Calculates stored capacitor energy from capacitance and voltage.
Capacitor charge
Calculates capacitor charge from capacitance and voltage.
Capacitor voltage from charge
Calculates capacitor voltage from charge and capacitance.
Parallel-plate capacitor
Calculates ideal parallel-plate capacitance from geometry and relative permittivity.
Capacitors in parallel
Calculates equivalent capacitance for capacitors connected in parallel.
Capacitors in series
Calculates equivalent capacitance for capacitors connected in series.
RC charging capacitor voltage
Calculates capacitor voltage during charging of an ideal RC circuit.
RC discharging capacitor voltage
Calculates capacitor voltage during discharge of an ideal RC circuit.
RC charging time to voltage
Calculates the time for a capacitor in an ideal RC circuit to reach a target voltage.
Inductor energy
Calculates stored energy in an ideal inductor from inductance and current.
RL time constant
Calculates the time constant of a simple resistor-inductor circuit.
Inductors in series
Calculates equivalent inductance for inductors connected in series.
Inductors in parallel
Calculates equivalent inductance for inductors connected in parallel.
Inductor voltage from current slope
Calculates voltage across an ideal inductor from inductance and current slope.
Long straight wire magnetic field
Calculates magnetic flux density around a long straight wire from current, distance and μr.
Circular loop center magnetic field
Calculates magnetic flux density at the center of an N-turn circular loop.
Ideal solenoid magnetic field
Calculates H, B and turn density for a long ideal solenoid.
Simple magnetic circuit
Calculates reluctance, MMF, flux and B/H for one core segment with an optional air gap.
Magnetic field energy density
Calculates linear magnetic field energy density from B and constant relative permeability μr.
Air-gap electromagnet force
Calculates ideal electromagnet force in a uniform gap from supplied B or from N, I and g.
RF wavelength
Calculates wavelength from frequency and velocity factor.
Antenna length from wavelength fraction
Calculates 1/4, 1/2 or 5/8 wavelength length from frequency and VF.
Free-space path loss
Calculates wavelength and FSPL in linear scale and dB for a supplied propagation speed.
RF link budget
Sums transmitter power, gains and losses in dB/dBm and calculates link margin.
Friis received power
Calculates received power from transmitted power, linear gains, wavelength and distance.
EIRP
Calculates equivalent isotropic radiated power in dBm from transmitter power, antenna gain and feeder loss.
Antenna effective aperture
Calculates antenna effective aperture from linear gain and wavelength.
Conductor skin depth
Calculates skin depth from frequency, resistivity and relative magnetic permeability.
Coaxial line impedance
Calculates impedance of a homogeneous non-magnetic coaxial line from geometry and dielectric permittivity.
Quarter-wave transformer
Calculates quarter-wave section impedance for real positive source and load impedances.
Simple microstrip impedance
Estimates microstrip impedance from trace width, substrate height and relative permittivity.
Reflection coefficient Γ
Calculates complex reflection coefficient from ZL and Z0 or from short/open-circuit cases.
VSWR from |Γ|
Calculates voltage standing wave ratio for |Γ| ≤ 1.
Return loss from |Γ|
Calculates return loss; for Γ = 0 it returns a structured +∞ dB result.
Mismatch loss from |Γ|
Calculates mismatch loss for |Γ| ≤ 1.
RF power balance
Calculates reflected and delivered power from incident power and |Γ|.
Rectangular waveguide TE10 cutoff
Calculates TE10 cutoff frequency and, above cutoff, guided wavelength.
Transmission-line electrical length
Calculates β and electrical length from physical length, frequency and VF.
Transformer secondary voltage
Calculates ideal transformer secondary voltage from turns ratio.
Transformer secondary voltage helper
Helper calculation for ideal transformer secondary voltage from primary voltage and turn counts.
Transformer secondary current
Calculates ideal transformer secondary current from turns ratio.
Transformer turns ratio
Calculates secondary-to-primary turns ratio.
Transformer efficiency
Calculates transformer efficiency from output and input power.
Transformer apparent power
Calculates primary and secondary apparent power from voltage and current.
Transformer copper loss
Calculates primary and secondary I²R winding losses from currents and resistances.
Transformer voltage regulation
Calculates voltage regulation as a fraction with percent display support.
Transformer efficiency from losses
Calculates efficiency from output power plus core, copper and additional losses.
Reflected transformer impedance
Calculates impedance reflected to the primary side of an ideal transformer.
Transformer secondary current from apparent power
Calculates ideal transformer secondary current from apparent power and secondary voltage.
Synchronous speed
Calculates motor synchronous speed from frequency and pole count.
Motor slip
Calculates slip from synchronous speed and rotor speed.
Motor slip percent
Helper calculation for percent slip from synchronous speed and rotor speed.
Motor torque from power and speed
Calculates approximate torque from power in kW and rotational speed.
Motor power from torque and speed
Calculates approximate power from torque and rotational speed.
Motor efficiency
Calculates motor efficiency as output power divided by input power.
Motor input power
Calculates input power from output power and efficiency.
DC motor back EMF
Calculates back EMF from supply voltage, armature current and armature resistance; with a back-EMF constant it also gives angular speed.
DC motor starting current and torque
Calculates current and torque at zero back EMF in a simple armature model.
Simple three-phase motor current
Calculates approximate three-phase motor current from power, voltage, power factor, and efficiency.
Battery energy in Wh
Estimates battery energy from nominal voltage and amp-hour capacity.
Battery runtime
Estimates runtime from battery capacity and load current.
Battery runtime with efficiency
Estimates runtime from capacity, system efficiency and load current.
Current from C-rate
Estimates current from C-rate and battery capacity.
Battery charge time
Roughly estimates charge time from capacity and charge current.
Series battery pack voltage
Calculates pack voltage from series cell count and cell voltage.
Parallel battery pack capacity
Calculates pack capacity from parallel cell count and single-cell capacity.
Battery voltage sag
Calculates approximate voltage drop across internal resistance at a given current.
Three-phase apparent power
Calculates theoretical apparent power of a balanced three-phase system.
Three-phase active power
Calculates theoretical active power of a balanced three-phase system.
Three-phase reactive power
Calculates theoretical reactive power from phase angle for a three-phase system.
Three-phase current from active power
Calculates theoretical line current from active power, line voltage and power factor.
Star phase voltage
Calculates theoretical phase voltage from line voltage in a star connection.
Delta phase current
Calculates theoretical phase current from line current in a delta connection.
Theoretical power factor correction
Calculates simplified theoretical correction power for improving power factor.
Power factor correction capacitor
Helper calculation for correction capacitance from active power and power-factor change; it is not a standards-based installation design.
Three-phase power from line voltage
Calculates active power of a balanced three-phase system from line-line voltage.
Theoretical DC voltage drop
Calculates approximate voltage drop for a simple DC circuit with outgoing and return conductors.
Voltage drop percent
Converts voltage drop to a percentage of nominal voltage.
Theoretical three-phase voltage drop
Calculates simplified voltage drop in a balanced three-phase system from per-length parameters.
Cable current density
Calculates current density as current divided by cross-sectional area.
Cable resistance from resistivity
Calculates resistance of a uniform conductor from resistivity, length, and cross-sectional area.
DC two-wire voltage drop
Helper calculation for DC voltage drop from current, resistance per meter and length; it is not standards-based conductor sizing.
Single-phase voltage drop
Helper calculation for simplified single-phase voltage drop from resistivity and area; it is not standards-based conductor sizing.
Three-phase voltage drop from resistivity
Helper calculation for simplified three-phase voltage drop from resistivity and area; it does not replace standards-based calculations.
Cable power loss
Helper calculation for cable power loss from current and resistance; it is not an allowable-load assessment.
AWG wire resistance and mass
Calculates AWG geometry, resistance, metal mass, and optional voltage drop and power loss.
AWG to conductor diameter and area
Calculates diameter and solid circular conductor area for AWG sizes from 4/0 to 40.
Cable ampacity after correction
Multiplies the manually provided base ampacity Iz by a correction factor.
Manual cable overload conditions check
Checks the provided Ib, In, Iz and I2 values without standards-table sizing.
Exact Iz lookup from user table
Looks up base ampacity Iz only for an exactly entered section in the user-supplied table.
Single-phase selection from user table
Selects the smallest entered section that meets the manual current conditions and voltage-drop limit.
Three-phase selection from user table
Selects the smallest entered section for a simplified balanced three-phase system.
Manual single-phase cable sizing check
Combines load current, manually corrected Iz, voltage drop and overload-condition checks.
Manual three-phase cable sizing check
Checks a balanced three-phase system with manually provided Iz, protective-device and voltage-drop data.
Manual WLZ check
Simplified manual WLZ check using installed power and demand factor.
Historical insulated-copper ampacity
Historical data from a 1938 publication. Exact Iz lookup for educational and comparative use only.
Historical minimum copper section
Historical data from a 1938 publication. Smallest-section selection without interpolation, for educational and comparative use only.
Historical underground three-core cable ampacity
Historical 1000 V cable data from a 1938 publication, for educational and comparative use only.
Manual Iz compared with historical value
Compares manually entered Iz with the historical insulated-copper value without PASS/FAIL judgement.
Simple fault current
Calculates approximate fault current from voltage and loop impedance.
Theoretical short-circuit power
Calculates approximate short-circuit power from voltage and impedance.
Theoretical maximum loop impedance
Calculates theoretical maximum loop impedance from voltage and trip current.
Simple protection fault-loop current
Calculates simplified current from voltage and loop impedance.
Simple fault-loop current
Helper calculation for current from voltage and loop impedance; it is not protection assessment or standards-based protective-device selection.
Simple touch voltage
Helper calculation for voltage from fault current and resistance; it is not a standards-based safety interpretation.
Theoretical touch voltage
Calculates approximate touch voltage from fault current and earth resistance.
Ground resistance from voltage and current
Calculates resistance as voltage divided by current in a simplified model.
Theoretical earth fault current
Calculates approximate earth fault current from voltage and loop impedance.
Force from mass and acceleration
Calculates force from Newton's second law of motion.
Weight from mass
Calculates weight force from mass and gravitational acceleration.
Torque from force and lever arm
Calculates torque from force and a perpendicular lever arm.
Work from force and distance
Calculates work done by a constant force over a distance.
Power from work and time
Calculates average power from work and time.
Power from force and velocity
Calculates power for a constant force acting along the direction of motion.
Efficiency
Calculates efficiency as output divided by input.
Kinetic energy
Calculates kinetic energy from mass and velocity.
Potential energy
Calculates gravitational potential energy from mass, gravity and height.
Momentum
Calculates linear momentum from mass and velocity.
Impulse
Calculates impulse from force and duration.
Angular velocity from RPM
Converts rotational speed in revolutions per minute to angular velocity.
RPM from angular velocity
Converts angular velocity to revolutions per minute.
Linear speed from RPM and diameter
Calculates tangential linear speed from rotational speed and diameter.
Centripetal force
Calculates centripetal force for circular motion.
Perfectly elastic collision 1D
Calculates a one-dimensional elastic collision of two bodies.
Perfectly inelastic collision 1D
Calculates a collision after which both bodies move with a common velocity.
Coefficient of restitution
Calculates the ratio of relative separation to approach speed in 1D.
Terminal velocity with quadratic drag
Calculates terminal velocity, weight, and drag force at terminal conditions.
Ideal lever mechanical advantage
Calculates load force and ideal mechanical advantage of a lever.
Ideal pulley system
Calculates ideal effort force and rope distance from the number of supporting segments.
2D force components
Resolves a force into X and Y components from an angle.
Resultant of two perpendicular forces
Calculates resultant force and angle from perpendicular force components.
Moment about a point 2D
Calculates moment from force and perpendicular lever arm.
Inclined plane components
Calculates parallel and normal weight components on an incline.
Force to move with friction
Calculates simplified friction force from normal force and friction coefficient.
Distance in uniform motion
Calculates distance from velocity and time for uniform motion.
Average velocity
Calculates average velocity from distance and time.
Acceleration
Calculates acceleration from velocity change and time.
Final velocity with uniform acceleration
Calculates final velocity from initial velocity, acceleration, and time.
Distance with uniform acceleration
Calculates distance from initial velocity, constant acceleration, and time.
Braking distance with reaction
Calculates reaction distance, braking distance, and total stopping distance for a simplified model.
Projectile motion
Calculates basic projectile-motion quantities without air resistance.
Free fall
Calculates vertical motion at constant gravitational acceleration using a positive-downward convention.
Simple pendulum
Calculates the period and frequency of a simple pendulum in the small-angle approximation.
Rotational kinetic energy
Calculates rotational kinetic energy of a rigid body.
Torque from inertia and angular acceleration
Calculates torque required for an angular acceleration.
Mass moment of inertia of a disc
Calculates axial mass moment of inertia of a uniform solid disc.
Mass moment of inertia of a rod about center
Calculates mass moment of inertia of a uniform rod about its center.
Mass moment of inertia of a ring
Calculates axial mass moment of inertia of a thin ring.
Mass-spring natural frequency
Calculates simplified undamped natural frequency of a mass-spring system.
Circle area
Calculates circle area from diameter.
Circle circumference
Calculates circle circumference from diameter.
Annulus area
Calculates annulus area from outer and inner diameters.
Rectangle area
Calculates rectangle area from width and height.
Triangle area
Calculates triangle area from base and height.
Trapezoid area
Calculates trapezoid area from two parallel sides and height.
Cylinder volume
Calculates cylinder volume from diameter and length.
Hollow cylinder volume
Calculates hollow cylinder volume from outer diameter, inner diameter, and length.
Sphere volume
Calculates sphere volume from radius.
Cone volume
Calculates cone volume from radius and height.
Mass from volume and density
Calculates mass from volume and density.
Rectangle area moment of inertia
Calculates rectangular area moment of inertia.
Circle area moment of inertia
Calculates solid circular area moment of inertia.
Tube area moment of inertia
Calculates tube area moment of inertia.
Solid shaft polar moment
Calculates polar moment of inertia for a solid circular shaft.
Hollow shaft polar moment
Calculates polar moment of inertia for a hollow circular shaft.
Rectangle section modulus
Calculates rectangular section modulus for bending.
Circle section modulus
Calculates solid circular section modulus.
Tube section modulus
Calculates tube section modulus.
Simply supported beam reactions - point load
Calculates support reactions for a point load at any position.
Simply supported beam - center load
Calculates reactions and maximum moment for a centered point load.
Simply supported beam - UDL reactions
Calculates reactions and maximum moment for a uniformly distributed load.
Beam UDL reactions
Calculates reactions A and B for a simply supported beam with a uniform load over the full span.
Beam UDL maximum moment
Calculates the maximum bending moment of a simply supported beam under uniform load.
Beam UDL maximum deflection
Calculates the maximum deflection of a simply supported beam under uniform load.
Simply supported center-load max deflection
Calculates maximum deflection of a simply supported beam with a centered point load.
Simply supported UDL max deflection
Calculates maximum deflection of a simply supported beam under a uniformly distributed load.
Cantilever end-load reaction
Calculates reaction and fixed-end moment for a cantilever with an end load.
Cantilever end-load deflection
Calculates free-end deflection of a cantilever loaded by an end point force.
Cantilever UDL deflection
Calculates free-end deflection of a cantilever under a uniformly distributed load.
Cantilever UDL maximum moment
Calculates the maximum fixed-end moment of a cantilever under uniform load.
Required section modulus
Calculates required section modulus from bending moment and allowable stress.
Allowable beam moment
Calculates allowable bending moment from allowable stress and section modulus.
Beam bending stress
Calculates bending stress from bending moment and section modulus.
Required moment of inertia - center load
Calculates required second moment of area for a deflection limit on a simply supported beam.
Simply supported beam reactions from point load at distance
Calculates support reactions A and B for a point load placed at a given distance from support A.
Simply supported beam maximum moment from center load
Calculates the maximum bending moment for a simply supported beam with a centered point load.
Cantilever maximum moment from end load
Calculates the maximum fixed-end moment of a cantilever with a point load at the free end.
Simply supported beam - linearly varying distributed load
Calculates reactions, resultant load, shear, point moment, and maximum moment for triangular, trapezoidal, or uniform distributed load.
Fixed-fixed beam - center point load
Calculates reactions, fixed-end moments, midspan moment, and maximum deflection for a centered point load on a fixed-fixed beam.
Fixed-fixed beam - UDL
Calculates reactions, fixed-end moments, midspan moment, and maximum deflection for a full-span uniform load.
Propped cantilever beam - UDL
Calculates reactions, fixed-end moment, and maximum positive moment for a cantilever fixed at A and propped at B.
Overhanging beam - end point load
Calculates support reactions and moment at support B for a point load at the end of an overhang beyond support B.
Simply supported beam - two point loads
Calculates reactions and moments at two point loads, selecting the largest absolute moment value.
Beam deflection limit ratio
Calculates allowable deflection from span and limit ratio, plus utilization, margin, and pass flag.
Bolt tensile stress
Calculates tensile stress from axial force and bolt stress area.
Bolt shear stress - single shear
Calculates bolt shear stress for a single shear plane.
Bolt shear stress - double shear
Calculates bolt shear stress for two shear planes.
Bolt preload from torque
Estimates bolt preload from tightening torque, nut factor K, and nominal diameter.
Bolt torque from preload
Estimates tightening torque from preload force, nut factor K, and nominal diameter.
Required bolt count in tension
Calculates the minimum bolt count for tensile loading by rounding up.
Required bolt count in shear
Calculates the minimum bolt count for shear loading by rounding up.
Bolt bearing pressure
Calculates average bearing pressure from force, bolt diameter, and plate thickness.
Bolt factor of safety
Calculates bolt safety factor as allowable stress divided by actual stress.
Bolt preload stress
Calculates average bolt stress as preload divided by tensile stress area.
Simple bolt joint safety factor
Calculates the factor as allowable load divided by applied load.
Simple bolt joint load share
Calculates bolt stiffness, load-share factor, bolt load increase, remaining clamp force, and separation flag.
Bolt joint separation load
Calculates separation load from preload and the stiffness-based load-share factor.
Torque from power and rpm
Calculates torque from power and rotational speed.
Power from torque and rpm
Calculates power from torque and rotational speed.
Solid shaft torsional stress
Calculates maximum shear stress in a solid circular shaft.
Hollow shaft torsional stress
Calculates maximum shear stress in a hollow circular shaft.
Required solid shaft diameter
Calculates required solid shaft diameter from torque and allowable shear stress.
Shaft twist angle from polar moment
Calculates shaft twist angle from torque, length, shear modulus, and polar moment of inertia.
Solid shaft shear stress
Calculates maximum shear stress in a solid circular shaft from torque.
Shaft diameter from torque and stress
Calculates required solid circular shaft diameter from torque and allowable shear stress.
Solid shaft angle of twist
Calculates twist angle for a solid circular shaft.
Hollow shaft angle of twist
Calculates twist angle for a hollow circular shaft.
Shaft combined bending and torsion von Mises
Calculates von Mises equivalent stress for a solid shaft under bending and torsion.
Key shear stress
Calculates simplified key shear stress from shaft torque.
Key bearing pressure
Calculates simplified key bearing pressure from shaft torque.
Required key length from shear and bearing
Calculates required key length as the larger of the shear and bearing-pressure requirements.
Shaft critical speed for a single mass
Calculates simplified critical speed from gravity and static deflection.
Spring force from deflection
Calculates linear spring force from stiffness and deflection.
Spring deflection from force
Calculates linear spring deflection from force and stiffness.
Spring energy
Calculates energy stored in a linear spring.
Spring stored energy
Calculates energy stored in a linear spring from spring rate and deflection.
Spring solid height
Calculates spring solid height as wire diameter multiplied by total coils.
Springs in parallel
Sums the stiffnesses of springs connected in parallel.
Springs in series
Calculates equivalent stiffness for springs connected in series.
Coil spring rate
Calculates simplified stiffness of a cylindrical helical spring.
Spring index
Calculates the ratio of mean coil diameter to wire diameter.
Spring Wahl factor
Calculates spring index and Wahl factor from coil geometry.
Helical spring shear stress with Wahl factor
Calculates helical spring shear stress with Wahl correction.
Compression spring available travel
Calculates available travel from free length, solid height, and required clearance.
Torsion spring rate
Calculates simplified angular rate and torque for a torsion spring.
Torsion spring bending stress
Calculates inner and outer fiber bending stress for a torsion spring.
Mass-spring natural frequency
Calculates undamped natural frequency of a mass-spring system.
Bearing L10 life in revolutions
Calculates simplified L10 life from dynamic load rating, equivalent load, and life exponent.
Bearing L10 life in hours
Converts life expressed in revolutions to operating hours at constant rotational speed.
Bearing static safety factor
Calculates static safety factor from static load rating and static equivalent load.
Plain bearing PV value
Calculates PV value as pressure multiplied by sliding velocity.
Ball bearing L10 life
Calculates simplified ball bearing L10 life from dynamic load rating and load.
Roller bearing L10 life
Calculates simplified roller bearing L10 life using the 10/3 exponent.
Bearing life in hours
Converts revolutions to operating time at constant rotational speed.
Required ball bearing dynamic capacity
Calculates required dynamic capacity C for a ball bearing and target L10 life.
Simple bearing equivalent dynamic load
Calculates simplified equivalent dynamic load from radial load, axial load, and X/Y factors.
Reliability-adjusted bearing life
Multiplies basic L10 life by a user-entered reliability factor a1.
General required bearing dynamic capacity
Calculates required dynamic capacity C from load, required life, and user-entered exponent p; use p=3 for ball bearings and p=10/3 for roller bearings.
Bearing viscosity ratio kappa
Calculates kappa as operating kinematic viscosity divided by reference kinematic viscosity.
Friction force
Calculates friction force from normal force and friction coefficient.
Friction power loss
Calculates power dissipated by friction for a force and sliding speed.
Braking energy
Calculates kinetic energy that must be dissipated during braking.
Braking distance from friction
Estimates braking distance with constant friction coefficient and gravity.
Braking time from deceleration
Calculates braking time from initial velocity and constant deceleration.
Brake torque
Calculates brake torque from braking force and effective radius.
Simple brake friction torque
Calculates brake friction torque from friction coefficient, normal force, and effective radius.
Simple clutch torque capacity
Estimates clutch torque capacity from friction, clamp force, mean radius, and surface count.
Belt drive ratio
Calculates ideal ratio from two pulley diameters.
Pulley output rpm
Calculates output rpm from input rpm and pulley diameters.
Belt speed
Calculates belt linear speed from pulley diameter and rpm.
Open belt drive length
Estimates belt length for an open belt drive.
Belt tangential force
Calculates tangential force from power and belt speed.
Chain drive ratio
Calculates ideal ratio from sprocket tooth counts.
Chain speed
Calculates chain speed from pitch, sprocket teeth, and rpm.
Roller chain length
Calculates theoretical roller chain length and the nearest even pitch count.
Belt tension force ratio and power
Calculates tension force ratio, tight-side tension force, and transmitted power from the capstan equation.
Gear ratio
Calculates ideal gear ratio from driven and driver tooth counts.
Gear output rpm
Calculates output speed from input speed and gear ratio.
Gear output torque
Calculates idealized output torque from input torque, gear ratio, and efficiency.
Gear module
Calculates gear module from pitch diameter and tooth count.
Gear pitch diameter
Calculates pitch diameter from module and tooth count.
Gear center distance
Calculates center distance from two pitch diameters.
External gear center distance
Calculates center distance from module and tooth counts for two external gears.
Gear base circle diameter
Calculates base circle diameter from pitch diameter and pressure angle.
Gear train output speed
Calculates output speed from input speed and gear ratio.
Gear tangential force
Calculates tangential force from torque and pitch diameter.
Spur gear mesh forces
Calculates tangential, radial, and normal mesh forces from torque, pitch diameter, and pressure angle.
Spur gear radial force
Calculates radial force from tangential force and pressure angle.
Helical gear axial force
Calculates axial force from tangential force and helix angle.
Multi-stage gear ratio
Multiplies the ratios of consecutive gear stages.
Multi-stage gear efficiency
Multiplies the efficiencies of consecutive gear stages.
Spur gear Lewis bending stress
Calculates simplified tooth bending stress using a user-entered Lewis factor.
Simplified spur gear contact stress
Calculates simplified, non-code contact stress with a user-entered elastic coefficient.
Bevel gear pitch angles
Calculates bevel gear pitch angles for 90-degree intersecting shafts.
Simple worm gear efficiency
Calculates worm-driven worm gear efficiency and self-locking flag.
Dimension tolerance
Calculates tolerance width and mean dimension from upper and lower limit dimensions.
Clearance fit min and max
Calculates minimum and maximum clearance from hole and shaft limit dimensions.
Interference fit min and max
Calculates minimum and maximum interference from hole and shaft limit dimensions.
Measurement percent error
Calculates absolute percent error relative to a reference value.
Tolerance midpoint
Calculates the midpoint from upper and lower limit dimensions.
Clearance from hole and shaft diameter
Calculates clearance as the difference between hole diameter and shaft diameter.
Cutting speed
Calculates cutting speed from diameter and spindle rpm.
Spindle rpm from cutting speed
Calculates spindle rpm from cutting speed and diameter.
Milling feed rate
Calculates milling feed rate from feed per tooth, tooth count, and rpm.
Turning feed rate
Calculates turning feed rate from feed per revolution and rpm.
Drilling time
Calculates drilling time from drilling depth and feed rate.
Turning time
Calculates turning time from cutting length and feed rate.
Thread pitch from TPI
Converts threads per inch to metric pitch.
TPI from thread pitch
Converts metric pitch to threads per inch.
Simple metric tap drill size
Estimates tap drill diameter as nominal diameter minus pitch.
Cylindrical stock volume conservation in upsetting
Calculates idealized solid cylindrical stock geometry under constant-volume upsetting.
Preliminary one-blow upsetting geometry screening
Checks L/d, D/d, and e/d proportions against FIA Rule 1, Rule 2, or Rule 3.
Normal stress
Calculates normal stress from axial force and cross-sectional area.
Shear stress
Calculates shear stress from force and cross-sectional area.
Strain
Calculates engineering strain from change in length and original length.
Hooke's law stress
Calculates elastic stress from Young's modulus and strain.
Axial elongation
Calculates axial elongation from force, length, area and Young's modulus.
Factor of safety
Calculates the safety factor as allowable stress divided by actual stress.
Allowable stress from yield strength
Calculates allowable stress as yield strength divided by safety factor.
Required area from force and stress
Calculates required area from force and allowable stress.
Required rod diameter in tension
Calculates minimum solid rod diameter from force and allowable stress.
Bearing pressure
Calculates average bearing pressure from force and projected area.
Pin single shear stress
Calculates average pin shear stress for one shear plane.
Pin double shear stress
Calculates average pin shear stress for two shear planes.
Pin bearing pressure
Calculates average pin bearing pressure from force, diameter, and member thickness.
Thin-wall pressure vessel stresses
Calculates hoop and longitudinal stress in a thin-walled closed cylinder from internal pressure, radius and wall thickness.
Bending stress
Calculates bending stress from bending moment and section modulus.
Torsional shear stress in solid shaft
Calculates maximum torsional shear stress in a solid circular shaft.
Torsional shear stress in hollow shaft
Calculates maximum torsional shear stress in a hollow circular shaft.
Shaft angle of twist
Calculates shaft twist angle from torque, length, shear modulus and polar moment.
Von Mises plane stress
Calculates von Mises equivalent stress for plane stress.
Tresca plane stress
Calculates Tresca equivalent stress for plane stress with the third principal stress set to zero.
Euler buckling load
Calculates ideal Euler critical buckling load.
Slenderness ratio
Calculates slenderness as effective length divided by radius of gyration.
Axial strain energy
Calculates strain energy for an axially loaded member.
Plane stress transformation
Transforms sigma_x, sigma_y, and tau_xy for a specified axis angle theta.
Principal stresses 2D
Calculates the two principal stresses, maximum in-plane shear, and principal-axis direction for a plane stress state.
Maximum in-plane shear stress
Calculates the maximum in-plane shear stress of a plane stress state.
Principal directions 2D
Finds the two perpendicular principal directions of a plane stress state.
Basic stress-intensity factor
Calculates K = Y * sigma * sqrt(pi * a) with a user-provided Y.
Critical crack length
Finds the crack length at which K reaches the specified KIC.
Margin against KIC
Calculates KIC/K as a simple margin against fracture toughness.
Fillet weld throat thickness
Calculates simplified fillet weld throat thickness from leg size.
Fillet weld throat area
Calculates effective fillet weld throat area from leg size and weld length.
Weld shear stress
Calculates average weld shear stress from force and throat area.
Required weld length for shear
Estimates required fillet weld length from force, allowable shear stress, and leg size.
Weld factor of safety
Calculates factor of safety as allowable stress divided by actual stress.
Weld line load
Calculates average line load as force divided by weld length.
Rectangular weld group line properties
Calculates length, Ix/Iy line moments, and J for a closed rectangular weld group.
Eccentric rectangular weld group
Estimates the largest corner line load in a closed rectangular weld group and the required throat.
Force from g-load
Calculates inertial force from mass, g-load factor, and gravity.
G-load from acceleration
Calculates g-load factor as acceleration divided by gravity.
Material wave speed in a rod
Estimates longitudinal wave speed from Young's modulus and density.
Explicit time step estimate
Estimates time step from characteristic length and wave speed.
Critical timestep from element size
Estimates critical timestep from element size and wave speed.
Element mass from density and volume
Calculates element mass from density and volume.
FEM kinetic energy
Calculates kinetic energy from mass and velocity.
Energy ratio check
Calculates the ratio of two energy values for a quick result check.
Explicit stable time step from wave speed
Calculates a simplified stable time step as characteristic length divided by wave speed.
Wave speed from elastic modulus and density
CAE helper for estimating wave speed; it does not validate the model or mesh.
Explicit time step from element length
CAE helper for estimating an explicit time step from characteristic length; it does not validate model stability.
Explicit time step from material
CAE helper combining element length and material wave speed; it does not validate solver settings.
Simple mass scaling factor
CAE helper showing a mass-change indicator for a target time step; it is not an automatic mass-scaling recommendation.
Element aspect ratio
CAE helper for a simple mesh metric; it does not judge correctness or overall model quality.
Mesh element count for a box
CAE helper for rough element counting in a box-shaped volume; it does not validate the mesh.
Simple strain rate
CAE helper for converting strain change to rate; it does not validate the load history.
Engineering to true strain
CAE helper for strain conversion; it does not validate the material curve.
Engineering to true stress
CAE helper for stress conversion; it does not validate material data.
Kinetic to internal energy ratio
CAE helper for monitoring an energy share; it does not validate the model energy balance.
Hourglass to internal energy ratio
CAE helper for monitoring hourglass energy; it does not validate element quality or the model.
Plastic work density
CAE helper for a simple plastic work per volume estimate; it does not validate the material model.
ETAN from bilinear segment
Calculates hardening modulus H and tangent modulus ETAN from two material-curve points or from an E-H pair.
Cowper-Symonds dynamic yield
Calculates the dynamic increase factor and scaled yield stress from C and p parameters.
Pressure from force and area
Calculates pressure as force divided by area.
Force from pressure and area
Calculates force from pressure and effective area.
Absolute pressure from gauge pressure
Calculates absolute pressure as gauge pressure plus atmospheric pressure.
Density from specific gravity
Calculates density from specific gravity and a user-supplied reference density.
Specific gravity from density
Calculates specific gravity from density and a user-supplied reference density.
Hydrostatic pressure from density and height
Calculates hydrostatic pressure from fluid density, gravity, and fluid column height.
Hydrostatic force from pressure and area
Calculates ideal hydrostatic force acting on the specified area.
Hydrostatic force on vertical wall
Calculates auxiliary hydrostatic force on a vertical surface from density, gravity, centroid depth, and area.
Buoyant force
Calculates buoyant force from fluid density, gravity, and displaced volume.
Volumetric flow rate
Calculates volumetric flow from area and velocity.
Pipe flow velocity
Calculates average pipe velocity from flow rate and pipe diameter.
Reynolds number
Calculates Reynolds number from density, velocity, diameter, and dynamic viscosity.
Dynamic pressure
Calculates dynamic pressure from fluid density and flow velocity.
Mass flow rate
Calculates mass flow rate from density and volumetric flow.
Velocity from continuity equation
Calculates flow velocity from volumetric flow and cross-sectional area.
Area from flow and velocity
Calculates required cross-sectional area from volumetric flow and velocity.
Pressure from ideal Bernoulli equation
Calculates pressure at the second point for ideal lossless flow.
Pipe cross-section area
Calculates circular pipe cross-section area from internal diameter.
Pipe diameter from area
Calculates pipe diameter from circular cross-section area.
Pipe velocity from flow and diameter
Calculates average velocity in a full circular pipe from volumetric flow rate and diameter.
Pipe diameter from flow and velocity
Calculates pipe diameter from volumetric flow and average velocity.
Pipe flow from diameter and velocity
Calculates volumetric pipe flow from diameter and average velocity.
Pipe volume
Calculates internal volume of a straight circular pipe from diameter and length.
Piston area
Calculates circular piston area from diameter.
Hydraulic cylinder force
Calculates ideal cylinder extension force from pressure and piston diameter.
Double-acting cylinder retract force
Calculates retract force from the annular piston area.
Cylinder speed from flow
Calculates motion speed from volumetric flow and piston area.
Hydraulic power
Calculates ideal hydraulic power from pressure and flow rate.
Hydraulic pressure from force and area
Calculates hydraulic pressure from force and effective area.
Hydraulic area from force and pressure
Calculates required effective area from force and pressure.
Cylinder bore from force and pressure
Calculates cylinder bore diameter from required force and pressure.
Cylinder force from bore and pressure
Calculates ideal extension force from pressure and cylinder bore.
Cylinder annulus area
Calculates rod-side annulus area from bore and rod diameter.
Cylinder retract force from bore, rod, and pressure
Calculates ideal retract force from pressure and annulus area.
Cylinder flow from speed and area
Calculates required volumetric flow from motion speed and effective area.
Cylinder stroke time
Calculates stroke time from stroke length and motion speed.
Hydraulic motor torque
Calculates ideal hydraulic motor torque from pressure drop and displacement.
Hydraulic motor speed
Calculates ideal hydraulic motor rotational speed from flow rate and displacement.
Darcy-Weisbach pressure loss
Calculates pipe pressure loss with the Darcy-Weisbach equation.
Darcy pressure drop
Calculates pipe pressure drop from friction factor, length, diameter, density, and velocity.
Head loss from pressure drop
Converts pressure drop to head loss for known density and gravity.
Pressure drop from head loss
Converts head loss to pressure drop for known density and gravity.
Minor-loss pressure drop
Calculates minor-loss pressure drop from coefficient K and dynamic pressure.
Minor-loss head
Calculates minor-loss head from coefficient K, velocity, and gravity.
Total pressure loss
Sums major and minor pressure losses.
Laminar-flow friction factor
Calculates the Darcy friction factor for laminar flow in a circular pipe.
Swamee-Jain friction factor
Calculates an approximate Darcy friction factor for turbulent pipe flow.
Hazen-Williams head loss
Calculates empirical head loss for water flow in a pipe using SI units.
Minor-loss equivalent length
Converts a minor-loss coefficient K to equivalent pipe length for a given diameter and friction factor.
Multiple pipe segments total loss
Sums head and pressure losses for several pipe segments carrying the same flow.
Colebrook-White friction factor
Iteratively solves the Colebrook-White equation.
Pipe flow and pressure loss
Combines flow, Reynolds number, friction and pressure losses.
Pipe diameter from allowed pressure drop
Solves diameter by bisection using the existing Colebrook-White core.
Hagen-Poiseuille flow
Laminar flow in a circular pipe.
Stokes drag law
Drag force on a spherical particle.
Stokes terminal velocity
Terminal velocity of a spherical particle.
Pitot tube
Velocity from differential pressure.
Venturi tube
Flow through a Venturi restriction.
Höppler falling-ball viscometer — dynamic viscosity
Calculates dynamic viscosity from viscometer constant, density difference, and ball fall time.
Ubbelohde capillary viscometer — kinematic viscosity
Calculates kinematic viscosity from capillary constant and flow time, and optionally dynamic viscosity from density.
Water hammer
First pressure-surge approximation using the Zhukovsky equation.
NPSHa and NPSH margin
Calculates NPSHa from absolute pressure and compares it with manufacturer NPSHr.
Pump affinity laws
Estimates the change in the same pump's parameters with speed.
Pumps in series
Ideal head addition at a common flow.
Pumps in parallel
Ideal flow addition at a common head.
Cv and Kv conversion
Converts valve flow coefficients between Cv and Kv conventions without manufacturer tables.
Pump operating point for quadratic curves
Intersects a simplified pump curve with a quadratic system curve.
Pump hydraulic power
Calculates hydraulic power from density, gravity, flow rate, and pump head.
Pump shaft power
Calculates required shaft power from hydraulic power and efficiency.
Pump efficiency
Calculates efficiency from hydraulic power and shaft power.
Pump head from pressure
Converts pump pressure rise to head.
Pump pressure from head
Converts pump head to pressure rise.
Basic pump specific speed
Calculates a simplified comparative pump specific-speed indicator.
Valve flow from Cv
Estimates liquid flow through a valve from Cv, pressure drop, and specific gravity.
Valve pressure drop from Cv
Estimates liquid pressure drop through a valve from flow rate, Cv, and specific gravity.
Valve Kv flow
Simplified liquid valve flow calculator from Kv, pressure drop in bar, and specific gravity.
Valve Cv flow
Simplified liquid valve flow calculator from Cv, pressure drop in psi, and specific gravity.
Orifice flow rate
Calculates indicative flow from Cd, area, pressure drop, and density.
Orifice pressure drop
Calculates indicative pressure drop from flow rate, Cd, area, and density.
Jet velocity from pressure
Calculates ideal jet velocity from pressure drop and density.
Nozzle exit velocity
Calculates ideal nozzle exit velocity from pressure drop and liquid density.
Jet force
Calculates simplified jet force from density, volumetric flow rate, and velocity.
Ideal-gas choked nozzle mass flow
Calculates choked mass flow and the critical pressure ratio for an ideal gas.
Ideal gas pressure
Calculates pressure from the ideal gas law for amount of substance, temperature, and volume.
Ideal gas volume
Calculates volume from the ideal gas law for amount of substance, temperature, and pressure.
Boyle law final pressure
Calculates final pressure at constant temperature from initial pressure, initial volume, and final volume.
Boyle law final volume
Calculates final volume at constant temperature from initial pressure, initial volume, and final pressure.
Pneumatic cylinder force
Calculates ideal pneumatic cylinder force from pressure and effective area.
Pneumatic cylinder extend force
Calculates auxiliary ideal pneumatic cylinder extend force from pressure and piston area.
Pneumatic cylinder retract force
Calculates auxiliary ideal pneumatic cylinder retract force from pressure, piston area, and rod area.
Pneumatic cylinder air volume
Calculates auxiliary geometric air volume from piston area and cylinder stroke.
Pneumatic cycle air consumption
Calculates auxiliary geometric flow from extend volume, retract volume, and cycles per minute.
Pneumatic cylinder air consumption
Calculates simplified geometric air volume from area, stroke, and cycle count.
Simple free air consumption
Converts cylinder volume to indicative free-air volume from absolute pressure.
Isothermal compressor power
Calculates simplified ideal isothermal compression power from inlet pressure, flow, and outlet pressure.
Pressure ratio
Calculates the ratio of two absolute pressures.
Standard flow to actual flow
Converts simplified standard flow to actual flow with pressure and temperature correction.
Mach number
Calculates Mach number as the ratio of flow velocity to speed of sound.
Froude number
Calculates Froude number from velocity, gravity, and characteristic length.
Weber number
Calculates Weber number as the ratio of inertial effects to surface tension.
Euler number
Calculates Euler number from pressure drop, density, and velocity.
Cavitation number
Calculates auxiliary cavitation number from pressure, vapor pressure, density, and flow velocity.
Prandtl number
Calculates Prandtl number from dynamic viscosity, specific heat, and thermal conductivity.
Simple compressor power
Calculates auxiliary compressor power from pressure increase, flow, and efficiency; it is not device selection.
Simple receiver tank pressure decay
Calculates auxiliary receiver pressure decay; this is a diagnostic simplification, not an exact thermodynamic model.
Speed of sound in ideal gas
Calculates speed of sound from heat capacity ratio, specific gas constant, and temperature.
Stagnation temperature
Calculates stagnation temperature for an isentropic ideal-gas model.
Isentropic stagnation pressure
Calculates stagnation pressure for an isentropic ideal-gas model.
Choked pressure ratio
Calculates critical throat-to-stagnation pressure ratio for an ideal gas.
Hydraulic radius
Calculates hydraulic radius from flow area and wetted perimeter.
Manning flow rate
Calculates open-channel flow with Manning equation from area, hydraulic radius, and slope.
Manning open-channel flow
Calculates auxiliary open-channel flow from area, hydraulic radius, slope, and Manning coefficient.
Rectangular channel area
Calculates rectangular channel flow area from width and depth.
Rectangular channel wetted perimeter
Calculates rectangular channel wetted perimeter from width and depth.
Rectangular channel hydraulic radius
Calculates rectangular channel hydraulic radius from width and depth.
Rectangular channel critical depth
Calculates critical depth from flow rate and rectangular channel width.
Rectangular hydraulic jump
Calculates sequent depth and energy loss for a rectangular hydraulic jump.
Rectangular weir flow
Calculates rectangular-weir flow using a user-supplied discharge coefficient.
V-notch weir flow
Calculates V-notch weir flow from notch angle, head, and discharge coefficient.
Linear thermal expansion
Calculates length change from linear thermal expansion.
Final length from thermal expansion
Calculates final length after a temperature change.
Thermal power from heat and time
Calculates thermal power from heat energy and time.
Heat from power and time
Calculates heat energy from power and time.
Celsius to kelvin
Converts Celsius temperature to kelvin.
Kelvin to Celsius
Converts kelvin temperature to degrees Celsius.
Celsius to Fahrenheit
Converts Celsius temperature to degrees Fahrenheit.
Fahrenheit to Celsius
Converts Fahrenheit temperature to degrees Celsius.
Celsius difference to kelvin difference
Converts a Celsius temperature difference to a kelvin difference.
Heating energy
Calculates heat energy from mass, specific heat, and temperature change.
Heat from mass, specific heat and temperature change
Calculates heat energy from mass, specific heat, and temperature change.
Temperature change from heat
Calculates temperature change from heat energy, mass, and specific heat.
Specific heat from heat
Calculates specific heat from heat energy, mass, and temperature change.
Heat capacity
Calculates heat capacity from mass and specific heat.
Heat from heat capacity and temperature change
Calculates heat energy from heat capacity and temperature change.
Latent heat energy
Calculates phase-change energy from mass and specific latent heat.
Specific latent heat from energy and mass
Calculates specific latent heat from heat energy and mass.
Two-stream mixing temperature
Calculates final temperature for adiabatic two-stream mixing from heat-capacity-rate balance.
Heat transfer through a wall
Calculates heat transfer rate through a flat layer.
Convection heat transfer
Calculates convection heat transfer rate from h, area, and temperature difference.
Heat flux from power and area
Calculates heat flux from heat-transfer rate and area.
Heat-transfer rate from flux and area
Calculates heat-transfer rate from average heat flux and area.
Thermal resistance from temperature difference and power
Calculates thermal resistance from temperature difference and heat-transfer rate.
Thermal resistances in series
Sums three thermal resistances connected in series in a simple heat-transfer model.
Overall heat transfer coefficient from area resistance
Calculates U-value as the inverse of total area-specific thermal resistance.
Heat transfer from temperature difference and resistance
Calculates heat-transfer rate from temperature difference and thermal resistance.
Straight-fin efficiency
Calculates efficiency of a constant-section straight fin with an adiabatic tip.
Fin effectiveness
Calculates the ratio of fin heat transfer to bare-base heat transfer.
Heat removed by a fin
Calculates heat-transfer rate removed by a straight fin with an adiabatic tip.
Nusselt number
Calculates Nu from supplied h, L, and k without a convection correlation.
Grashof number
Calculates Gr from user-supplied properties.
Rayleigh number
Calculates Ra = Gr*Pr.
Schmidt number
Calculates Sc = nu/D.
Sherwood number
Calculates Sh = km*L/D without a mass-transfer correlation.
Thermal Peclet number
Calculates Pe_t = vL/alpha.
Mass Peclet number
Calculates Pe_m = vL/D.
Conduction heat rate through a flat wall
Calculates conduction heat rate through a flat layer.
Conduction heat flux through a flat wall
Calculates conduction heat flux through a flat layer.
Flat-wall conduction thermal resistance
Calculates conduction thermal resistance of a flat layer.
Conduction heat rate through a cylindrical wall
Calculates radial conduction heat rate through a cylindrical wall.
Cylindrical-wall conduction thermal resistance
Calculates radial conduction thermal resistance of a cylindrical wall.
Convection heat rate
Calculates convection heat rate from h, area, and temperature difference.
Convection heat flux
Calculates convection heat flux from h and temperature difference.
Convection coefficient from heat rate
Calculates heat transfer coefficient from heat rate, area, and temperature difference.
Convection thermal resistance
Calculates convection thermal resistance from h and area.
Blackbody radiation heat rate
Calculates ideal blackbody radiation heat rate between two temperatures.
Gray-body radiation heat rate
Calculates gray-body radiation heat rate with emissivity.
Gray-body radiation heat flux
Calculates gray-body radiation heat flux.
Emissivity from radiation heat rate
Calculates emissivity from radiation heat rate, area, and temperatures.
Constant-pressure heat
Calculates heat from mass, cp, and temperature change at constant pressure.
Constant-volume heat
Calculates heat from mass, cv, and temperature change at constant volume.
Ideal-gas internal energy change
Calculates ideal-gas internal energy change from mass, cv, and temperature change.
Ideal-gas enthalpy change
Calculates ideal-gas enthalpy change from mass, cp, and temperature change.
Thermal efficiency
Calculates thermal efficiency as useful work output divided by heat input.
Carnot efficiency
Calculates ideal Carnot-cycle efficiency from cold and hot reservoir temperatures.
Work from pressure and volume change
Calculates constant-pressure work from pressure and volume change.
Polytropic process work
Calculates ideal-gas polytropic process work for n not equal to 1.
Ideal Otto cycle
Calculates ideal Otto-cycle efficiency from compression ratio and κ.
Ideal Diesel cycle
Calculates ideal Diesel-cycle efficiency from compression ratio, cutoff ratio, and κ.
Ideal Brayton cycle
Calculates ideal Brayton efficiency; an optional inlet temperature gives compressor-outlet temperature.
Simplified Rankine cycle
Calculates an ideal Rankine-cycle balance from manually entered enthalpies h1–h4.
Ideal gas pressure from mass
Calculates ideal-gas pressure from mass, specific gas constant, temperature, and volume.
Ideal gas volume from mass
Calculates ideal-gas volume from mass, specific gas constant, temperature, and pressure.
Ideal gas temperature
Calculates ideal-gas absolute temperature from pressure, volume, mass, and specific gas constant.
Ideal gas mass
Calculates ideal-gas mass from pressure, volume, specific gas constant, and temperature.
Ideal gas density
Calculates ideal-gas density from pressure, specific gas constant, and temperature.
Specific gas constant from molar mass
Calculates the specific gas constant from the universal gas constant and molar mass.
Counterflow LMTD
Calculates the log-mean temperature difference for a counterflow heat exchanger.
Parallel-flow LMTD
Calculates the log-mean temperature difference for a parallel-flow heat exchanger.
Heat exchanger LMTD
Calculates log-mean temperature difference from two positive temperature differences.
Heat exchanger heat rate from LMTD
Calculates heat exchanger duty from U, area, and log-mean temperature difference.
Heat exchanger heat duty from LMTD
Calculates auxiliary heat exchanger duty from U, heat-transfer area, and LMTD.
Heat exchanger area from duty
Calculates required heat-transfer area from duty, U, and LMTD.
Heat exchanger duty from mass flow
Calculates fluid heat duty from mass flow, specific heat, and temperature change.
Fluid outlet temperature from heat
Calculates fluid outlet temperature from inlet temperature, heat rate, mass flow, and specific heat.
Heat exchanger effectiveness
Calculates heat exchanger effectiveness as actual heat rate divided by maximum possible heat rate.
NTU from U, area and Cmin
Calculates number of transfer units from U, area, and minimum heat capacity rate.
Counterflow epsilon-NTU heat exchanger
Calculates effectiveness and heat rate for a counterflow heat exchanger from UA and heat capacity rates.
Parallel-flow epsilon-NTU heat exchanger
Calculates effectiveness and heat rate for a parallel-flow heat exchanger from UA and heat capacity rates.
Thermal resistances of layers in series
Sums thermal resistances of multiple layers connected in series.
Overall U-value from area resistance
Calculates simplified overall heat transfer coefficient as the inverse of total area-specific thermal resistance.
Insulation heat loss through a flat wall
Calculates indicative heat loss through a flat barrier from area, temperature difference, and thermal resistance.
Required insulation resistance
Calculates required thermal resistance from allowable heat loss, area, and temperature difference.
Required insulation thickness
Calculates required insulation thickness from thermal resistance, conductivity, and area.
Pipe insulation heat loss
Calculates heat loss through a cylindrical pipe insulation layer from radial conduction resistance.
Sensible cooling load
Calculates cooling power from mass flow, specific heat, and temperature change.
Cooling water flow rate
Calculates required cooling-water mass flow from cooling power, specific heat, and temperature change.
Cooling time by lumped capacitance
Estimates time to reach a target temperature with a simplified lumped-capacitance model.
Newton cooling temperature
Calculates object temperature after a time in a simplified Newton cooling model.
Cooling energy removed
Calculates removed heat energy from mass, specific heat, and temperature change.
Cooling power from energy and time
Calculates average cooling power from removed energy and time.
Refrigerator COP
Calculates refrigeration COP as cooling power divided by input power.
Refrigeration COP
Calculates auxiliary refrigeration COP as cooling power divided by compressor power.
Heat pump COP
Calculates heat pump COP as heating power divided by input power.
Carnot refrigerator COP
Calculates ideal Carnot refrigeration COP from absolute temperatures.
Carnot heat pump COP
Calculates ideal Carnot heat pump COP from absolute temperatures.
Refrigeration capacity from mass flow
Calculates refrigeration capacity from refrigerant mass flow and enthalpy difference.
Refrigerant mass flow from capacity
Calculates required refrigerant mass flow from refrigeration capacity and enthalpy difference.
Refrigeration cycle from four enthalpies
Calculates evaporator heat, compressor work, condenser heat, COP, and mass flow from four user-provided enthalpies.
Refrigeration superheat and subcooling
Calculates suction superheat and liquid subcooling from user-provided temperatures.
Tons of refrigeration to kW
Converts tons of refrigeration TR to cooling power in kW.
kW to tons of refrigeration
Converts cooling power in kW to tons of refrigeration TR.
Fuel energy from mass and LHV
Calculates fuel chemical energy from mass and user-provided lower heating value.
Fuel energy from volume and LHV
Calculates fuel energy from volume and user-provided volumetric heating value.
Fuel power from mass flow and LHV
Calculates chemical fuel power from mass flow and lower heating value.
Fuel mass flow from power and LHV
Calculates fuel mass flow required for a given chemical power and LHV.
Boiler efficiency
Calculates indicative efficiency as useful heat output divided by fuel energy input.
Fuel consumption from heat output
Calculates fuel mass needed for a given heat output, efficiency, and LHV.
Air required from air-fuel ratio
Calculates air mass from user-provided air-fuel ratio and fuel mass.
Excess air percentage
Calculates excess air percentage from actual and theoretical air mass.
Water heating energy
Calculates heat required to warm water from mass, specific heat, and temperature change.
Water evaporation energy
Calculates energy required to evaporate water from mass and user-provided latent heat of vaporization.
Wet steam enthalpy
Calculates wet steam specific enthalpy from saturated-liquid enthalpy, vaporization enthalpy, and quality.
Steam quality from enthalpy
Calculates steam quality from specific enthalpy and user-provided saturation data.
Steam quality after throttling
Calculates outlet quality for isenthalpic throttling using user-provided saturation data.
Flash steam fraction
Calculates flash steam fraction from liquid enthalpy difference and outlet latent enthalpy.
Steam power from mass flow and enthalpy drop
Calculates theoretical steam power from mass flow and enthalpy drop.
Steam mass flow from power and enthalpy drop
Calculates steam mass flow required for a given power and enthalpy drop.
Condensate recovery energy
Calculates recovered heat energy from the temperature difference between condensate and makeup water.
Density from mass and volume
Calculates material density from mass and volume.
Part mass from density and volume
Calculates part mass from material density and volume.
Mass from density and volume
Calculates mass from material density and volume.
Volume from mass and density
Calculates material volume from mass and density.
Specific weight
Calculates specific weight as density multiplied by gravitational acceleration.
Material mass from area, thickness, and density
Calculates flat part mass from area, thickness, and material density.
Material cost from mass and price
Calculates material cost from mass and unit price per kilogram.
Specific strength
Calculates specific strength as strength divided by density.
Specific stiffness
Calculates specific stiffness as Young's modulus divided by density.
Strength-to-weight ratio
Calculates strength divided by material specific weight.
Poisson lateral strain
Calculates lateral strain from axial strain and Poisson ratio.
Bulk modulus from Young's modulus and Poisson ratio
Calculates bulk modulus from Young's modulus and Poisson ratio.
Young's modulus from stress and strain
Calculates Young's modulus as stress divided by strain.
Allowable stress from ultimate strength
Calculates simplified allowable stress from ultimate strength and safety factor.
Stress from force and area
Calculates stress as force divided by area.
Strain from length change
Calculates engineering strain as length change divided by original length.
Shear modulus from shear stress and strain
Calculates shear modulus as shear stress divided by shear strain.
Bulk modulus from pressure and volumetric strain
Calculates bulk modulus as pressure change divided by volumetric strain.
Poisson ratio from elastic constants
Calculates Poisson's ratio from Young's modulus and shear modulus.
Shear modulus from Young's modulus and Poisson ratio
Calculates shear modulus from Young's modulus and Poisson's ratio.
Stiffness-to-weight ratio
Calculates specific stiffness as Young's modulus divided by density.
Yield margin
Calculates margin as yield strength divided by working stress.
Ultimate margin
Calculates margin as ultimate strength divided by working stress.
Allowable stress from safety factor
Calculates allowable stress as strength divided by safety factor.
Linear thermal expansion
Calculates length change and final length for linear thermal expansion.
Area thermal expansion
Calculates area change and final area using beta = 2 * alpha.
Volume thermal expansion
Calculates volume change and final volume using beta = 3 * alpha.
Thermal diffusivity
Calculates thermal diffusivity from thermal conductivity, density, and specific heat.
Thermal resistance of a layer
Calculates thermal resistance of a flat layer from thickness, thermal conductivity, and area.
Thermal conductance of a layer
Calculates thermal conductance of a layer from conductivity, area, and thickness.
Biot number
Calculates the Biot number from h, characteristic length, and thermal conductivity.
Fourier number
Calculates the Fourier number from thermal diffusivity, time, and length.
Volumetric heat capacity
Calculates volumetric heat capacity from density and specific heat.
Steel bar mass
Calculates bar mass from cross-sectional area, length, and user-provided density.
Steel sheet mass
Calculates sheet mass from area, thickness, and user-provided density.
Steel tube mass
Calculates tube mass from user-provided diameters, length, and density; it does not use material databases.
Aluminum plate mass
Calculates aluminum plate mass from area, thickness, and user-provided density.
Aluminum profile mass
Calculates profile mass from user-provided cross-section area, length, and density.
Aluminum mass from volume
Calculates aluminum mass from volume and user-provided density; it does not use an alloy database.
Aluminum profile length from mass
Calculates profile length from user-provided mass, cross-section area, and density.
Aluminum sheet mass per area
Calculates sheet mass per unit area from user-provided thickness and density.
Plastic part shrinkage
Calculates percentage shrinkage from the mold dimension and finished part dimension.
Plastic thermal expansion
Calculates helper length change from user-provided initial length, expansion coefficient, and temperature change.
Plastic mold dimension from shrinkage
Calculates mold dimension from part dimension and user-provided shrinkage.
Plastic mass from volume and density
Calculates plastic mass from volume and user-provided density; it does not use a plastics database.
Volumetric shrinkage from linear shrinkage
Calculates volumetric shrinkage from linear shrinkage using a simplified isotropic three-direction model.
Composite rule-of-mixtures modulus
Calculates a simplified composite modulus from fiber volume fraction and fiber and matrix moduli.
Composite density by rule of mixtures
Calculates helper composite density from user-provided fiber volume fraction and fiber and matrix densities.
Composite constituent masses
Calculates fiber and matrix volumes, masses, theoretical density, and mass fractions from total volume and fiber volume fraction.
Stereology point counting
Estimates the volume fraction of an identifiable phase from the phase point count and total grid point count.
Laminate thickness from plies
Calculates helper laminate thickness from user-provided ply count and single-ply thickness.
Wood moisture content
Calculates wood moisture content from wet and dry mass relative to dry mass.
Wood board volume
Calculates helper rectangular board volume from user-provided dimensions.
Wood board mass
Calculates rectangular board mass from dimensions and user-provided density; it does not use wood species tables.
Wood density from mass and volume
Calculates wood density from user-provided mass and volume; it does not use species tables.
Board count from required volume
Calculates required volume divided by single-board volume without automatic rounding.
Wood dry mass from moisture
Calculates dry mass from wet mass and moisture content defined on a dry-mass basis.
Concrete water-cement ratio
Calculates the simple ratio of water mass to cement mass from user-provided values.
Concrete density from mass and volume
Calculates concrete density from user-provided mass and volume.
Concrete mix water mass
Calculates helper water mass from user-provided water-cement ratio and cement mass.
Fatigue stress amplitude
Calculates stress amplitude from maximum and minimum stress.
Fatigue mean stress
Calculates mean stress from maximum and minimum stress.
Fatigue stress ratio
Calculates the R ratio as minimum stress divided by maximum stress.
Simple Basquin cycles to failure
Estimates cycles from a simplified Basquin model; coefficients are user-provided.
Simple Goodman safety factor
Calculates a helper safety factor from a simple Goodman equation using user-provided values.
Soderberg fatigue safety factor
Calculates utilization and safety factor from a simplified Soderberg criterion.
Gerber fatigue safety factor
Calculates safety factor for proportional load scaling in a simplified Gerber criterion.
Notch sensitivity and fatigue factor
Calculates notch sensitivity and fatigue stress concentration from user-entered Kt and material constant.
Miner damage sum for three blocks
Calculates a helper Miner damage sum for three cycle blocks from user-provided values.
Paris-law crack propagation
Estimates cycles between a0 and af from the Paris law with user-provided C, m, and Y.
Vickers hardness from force and diagonal
Calculates HV hardness from force in newtons and indentation diagonal in millimeters.
Simple Brinell hardness
Calculates HB from force in kilogram-force and ball and indentation diameters in millimeters.
Vickers diagonal from hardness
Calculates indentation diagonal from force and HV hardness using the same Vickers relation.
Vickers force from hardness
Calculates force from HV hardness and indentation diagonal using the same Vickers relation.
Hardness difference percent
Calculates percent difference between new and reference hardness; it is not a hardness conversion table.
Corrosion rate from mass loss
Calculates simplified corrosion rate in mm/year from mass loss, density, area, and exposure time.
Mass loss from corrosion rate
Calculates helper mass loss from user-provided corrosion rate, density, area, and time.
Corrosion penetration depth
Calculates linear thickness loss from corrosion rate and time in years.
Remaining wall thickness after corrosion
Calculates remaining thickness as a mathematical value without an operational decision.
Corrosion mass loss percent
Calculates percent mass loss from initial and final mass.
Simple coating lifetime
Calculates a linear simplified coating lifetime without environmental effects or local damage.
Material specific property score
Calculates a simple score as property value divided by density.
Weighted score for three criteria
Calculates a notional weighted score from three user-provided scores and weights.
Material cost per volume
Calculates cost per unit volume from user-provided cost per mass and density.
Material strength cost index
Calculates a notional comparative strength index relative to density and cost per mass.
Material stiffness cost index
Calculates a notional comparative stiffness index relative to density and cost per mass.
Simplified thermal shock resistance index
Calculates a notional comparative thermal shock resistance index; it is not a criterion from a specific standard.
Steel member mass from area and length
Calculates steel member mass from cross-sectional area, length, and user-provided density.
Simple steel axial stress
Calculates axial stress as axial force divided by cross-sectional area.
Required steel area for axial force
Calculates required cross-sectional area from axial force and chosen allowable stress.
Simple steel column slenderness
Calculates slenderness as effective length divided by radius of gyration.
Euler buckling load of a steel column
Helper calculation of ideal Euler critical load; it is not code-based design or column capacity verification.
Required steel section modulus
Helper calculation of required section modulus from moment and allowable stress; it is not code-based design.
Slab self-weight
Calculates slab area load from thickness, density, and gravitational acceleration.
Reinforcement ratio of a rectangular section
Calculates reinforcement ratio from steel area, section width, and effective depth.
Simplified reinforced-concrete moment capacity
Estimates moment from steelArea * yieldStress * leverArm; this is not code-based design.
Concrete cover from effective depth
Calculates the geometric difference between total depth and effective depth.
RC bar count from area
Helper calculation of theoretical bar count from required steel area and single bar area; it is not code-based design.
Roof slope percent
Calculates roof slope percent from rise and horizontal run.
Roof angle from rise and run
Calculates roof pitch angle as arctangent of rise divided by run.
Roof area from plan area and angle
Converts roof plan area into approximate sloped roof area using the pitch angle.
Roof area from plan and slope
Calculates sloped roof area from plan area and roof angle plus required material area with waste.
Stair riser height
Calculates single riser height from total rise and riser count.
Stair slope angle
Calculates stair slope angle from riser height and tread depth.
Wall area with openings
Helper calculation of net wall area after subtracting openings; it is not code-based design.
Roof rafter length
Helper calculation of geometric rafter length from run and rise; it is not code-based design.
Blondel helper value
Helper calculation of stair geometry value 2h + s; it is not a code check or code-based design.
Soil unit weight
Calculates soil unit weight as sample weight divided by sample volume.
Vertical soil stress
Calculates simple vertical soil stress from unit weight and depth.
Simple lateral earth pressure
Simplified lateral pressure calculator from coefficient, unit weight, and depth; it is not code-based retaining-wall design.
Rankine active earth pressure with surcharge
Calculates an indicative active soil and surcharge resultant per meter of wall; it is not retaining-wall design.
Rankine passive earth pressure
Calculates an indicative passive pressure resultant per meter of wall from friction angle and soil unit weight.
Hydrostatic pressure behind wall
Calculates water-pressure resultant, resultant location, and base pressure for a given water height.
Infinite slope safety factor
Calculates an indicative infinite-slope safety factor from user-provided strength parameters and pore pressure.
Soil porosity
Helper calculation of porosity as void volume divided by total volume; it is not code-based design.
Soil gradation coefficients Cu and Cc
Calculates Cu = D60/D10 and Cc = D30^2/(D10*D60) from values read from a gradation curve.
Darcy flow through soil
Calculates gradient i = Δh/L, flow Q = k*A*i, and Darcy velocity q = k*i.
Constant-head permeability test
Calculates k = V*L/(A*Δh*t), where V is the measured flow volume.
Falling-head permeability test
Calculates k = (a*L/(A*t))*ln(h1/h2) for positive heads h1 > h2.
Consolidation time factor
Calculates T_v = c_v*t/H_dr^2 and inverse modes for time, c_v, and drainage path.
U to T_v consolidation approximation
Calculates approximate T_v from U: for U <= 0.60 it uses (pi/4)*U^2, for larger U it uses -0.933*log10(1-U)-0.085.
Boussinesq point-load stress
Calculates vertical stress σ_z below a point load P at radial distance r and depth z.
Bearing capacity with manual factors
Calculates q_ult = c*Nc + q*Nq + 0.5*gamma*B*Ngamma from manually supplied factors and multipliers.
Simple elastic settlement
Calculates S = q*B*(1-nu^2)*I_s/E_s with manually supplied influence factor I_s.
Concrete volume for a rectangular shape
Calculates concrete volume from the length, width, and height of an element.
Concrete volume for a slab
Calculates concrete volume from slab area and thickness.
Reinforcement mass from length and diameter
Calculates approximate reinforcing bar mass using the practical formula m = L * d² / 162.
Strip foundation volume
Calculates simple strip foundation volume from length, width, and depth.
Average soil bearing pressure
Calculates simple average soil pressure as load divided by base area.
Foundation eccentricity
Helper calculation of eccentricity from moment and vertical load; it is not code-based design or capacity verification.
Foundation average pressure
Helper calculation of average pressure as vertical load divided by area; it is not code-based design or soil capacity.
Rectangular footing eccentric pressure, one axis
Calculates average pressure, eccentricity, and edge pressures for a rectangular footing with one-axis moment.
Rectangular footing corner pressures
Calculates four corner pressure combinations for a rectangular footing with two-axis moments.
Simple single pile capacity
Calculates indicative pile capacity from user-supplied base resistance, shaft resistance, and safety factor.
General wind load
Calculates q = 0.5*rho*v^2, p = q*C_total, F = p*A, and M = F*e from manually supplied coefficients.
General snow load
Calculates s = μ_i*C_e*C_t*s_k from manually supplied coefficients and s_k.
Line load from area load and width
Converts an area load into a line load using tributary width.
Point load from line load
Converts a line load to a point load for assigned tributary length L_tr.
Total force from area load
Converts an area load to total force using F = p*A.
Point load from mass
Calculates a point load from mass and user-supplied gravitational acceleration.
Self-weight from density and volume
Calculates self-weight from density, volume, and gravitational acceleration.
Area load from mass and area
Distributes mass as an area load over a given area using the supplied gravitational acceleration.
Surface load from thickness and density
Calculates layer area load from thickness, density, and gravitational acceleration.
Total area load
Sums four signed area-load components using the user's sign convention.
Total line load
Sums four signed line-load components using the user's sign convention.
Column load from tributary area
Multiplies area load by tributary area to estimate a column load.
Load per support
Divides total load by support count without imposing a support type.
Manual linear load combination
Combines three line loads with factors entered manually by the user; it is not a combination from any specific code.
Block count for a wall
Estimates block count from wall area, block dimensions, and waste percentage.
Mortar volume for a wall
Estimates mortar volume from wall dimensions and mortar share percentage.
Concrete bags count
Helper estimate for bag count from concrete volume and one-bag yield; it is not code-based design.
Rectangular foundation formwork area
Helper estimate for side formwork area of a rectangular foundation; it is not code-based design.
Rectangular excavation volume
Helper estimate for rectangular excavation volume from dimensions; it is not code-based design.
Cost with waste factor
Helper estimate for total cost after adding a waste percentage; it is not code-based design.
Wall finish area
Calculates gross area, net area, and required material area for coat count and waste.
Asphalt mass from area and thickness
Calculates asphalt layer volume and mass from area, thickness, and user-supplied density.
Spindle speed from cutting speed
Calculates spindle speed from cutting speed and tool or workpiece diameter.
Cutting speed from spindle speed
Calculates cutting speed from diameter and spindle speed.
Feed rate from feed per revolution
Calculates feed rate from feed per revolution and spindle speed.
Machining power from force and speed
Calculates ideal cutting power as main cutting force multiplied by cutting speed.
Cutting power from MRR
Calculates helper cutting power from specific cutting energy and material removal rate.
Grinding wheel peripheral speed
Calculates grinding wheel peripheral speed from wheel diameter and rotational speed, or the reverse.
Taylor tool life
Calculates simplified tool life from Taylor's equation using constant, cutting speed, and exponent.
Taylor tool life
Calculates simplified tool life from Taylor's equation using constant, cutting speed, and exponent.
Machining cost per part with tool life
Estimates tool and machine cost per part from machining time and tool life.
EDM material removal rate
Calculates volumetric and mass EDM removal rate from mass loss, density, and machining time.
EDM electrode wear ratio
Calculates electrode loss, volumetric electrode wear rate, and volumetric EWR relative to removed workpiece volume.
EDM side gap and overcut
Calculates diametral overcut and radial side gap from electrode and measured hole diameters.
EDM hole taper
Calculates top and bottom gaps and geometric hole taper from two diameters and depth.
ECM current density
Calculates current density from current and active current-carrying area.
ECM Faraday material removal rate
Calculates theoretical and actual ECM mass and volumetric removal rates from Faraday's law, current efficiency, and material data.
Turning time
Calculates simple turning time from travel length and feed rate.
Turning material removal rate
Calculates turning material removal rate from diameter, depth of cut, feed per revolution, and spindle speed.
Turning time with approach
Calculates turning time from cut length, approach length, and feed rate.
Turning cutting force from power
Calculates cutting force from cutting power and cutting speed in a simplified model.
Turning pass count
Calculates the minimum pass count from radial allowance and depth per pass.
Turning removed volume
Calculates material volume removed in turning from diameter difference and cut length.
Milling feed rate
Calculates milling feed rate from feed per tooth, tooth count, and spindle speed.
Milling material removal rate
Calculates milling material removal rate from width of cut, depth of cut, and feed rate.
Milling cutting time
Calculates milling time from cut length, approach length, and feed rate.
Milling feed per tooth from feed rate
Calculates feed per tooth from feed rate, tooth count, and spindle speed.
Milling pass count
Calculates the minimum pass count from total depth and depth per pass.
Milling cutting power
Calculates cutting power from specific cutting energy and material removal rate.
Drilling time
Calculates simple drilling time from depth and feed rate.
Drilling material removal rate
Calculates drilling material removal rate from drill diameter and feed rate.
Drilling feed rate
Calculates drilling feed rate from feed per revolution and spindle speed.
Drilling spindle speed
Calculates spindle speed from cutting speed and drill diameter.
Drilling time with point allowance
Calculates drilling time from depth, drill-point allowance, and feed rate.
Drilling cutting power
Calculates cutting power from specific cutting energy and material removal rate.
Metric tap drill diameter
Estimates metric tap drill diameter as nominal diameter minus thread pitch.
Thread lead
Calculates thread lead from pitch and user-supplied number of starts.
Thread turns per length
Calculates turns for a given thread length and lead.
Thread helix angle
Calculates helix angle from lead and pitch diameter.
Thread engagement turns
Calculates engagement turns from engagement length and pitch.
Approximate metric thread depth
Calculates approximate thread depth from a pitch multiplier; it is not a standards-based inspection dimension.
Thread cutting time
Calculates simplified thread cutting time from thread length, approach length, and feed rate.
Generic thread stripping stress
Calculates thread shear area and shear stress from a user-entered effective shear perimeter.
Generic required thread engagement
Calculates required thread engagement from axial force, allowable shear stress, and effective shear perimeter.
Absolute measurement error
Calculates signed error as measured value minus reference value.
Relative measurement error percent
Calculates signed relative error from measured and reference values.
Tolerance band from limits
Calculates tolerance band width as upper limit minus lower limit.
Gauge half-resolution uncertainty
Estimates reading uncertainty as one half of the gauge resolution.
Simple Gage R&R percent
Calculates a helper Gage R&R percent as measurement system variation divided by total variation.
RSS measurement uncertainty
Calculates combined measurement uncertainty as root-sum-square of three components.
Diametrical true position
Calculates X/Y deviations and diametrical true position as 2 * sqrt(deltaX^2 + deltaY^2).
MMC bonus tolerance
Calculates bonus tolerance and total position tolerance for an explicitly selected hole or shaft.
Virtual condition
Calculates virtual condition for a hole or shaft from MMC size and position tolerance.
Theoretical turning roughness Ra
Estimates geometric Ra from feed per revolution and tool nose radius.
Simple milling scallop height
Calculates simple scallop height from step-over and tool radius.
Ball end mill scallop height
Calculates geometric scallop height for a ball end mill from step-over and radius.
Production batch time
Calculates total batch time from setup time, quantity, and cycle time.
Takt time
Calculates required time per part from available time and required quantity.
Machine hour cost
Calculates simple machine cost from machine time and hourly rate.
Setup cost per part
Divides setup cost by batch quantity.
Simple part cost
Sums material, machine, labor, and tool cost in a simple part-cost estimate.
Required machines count
Calculates required machine count from output requirement, cycle time, and available time.
Labor cost
Calculates simple labor cost from hours and hourly rate.
Manufacturing operation and batch cost
Calculates one-operation batch cost, unit cost, price from markup, price from margin, and minimum batch size for a target unit cost.
Sheet metal bend allowance
Calculates BA = θ_rad × (Ri + Kt) for a bend angle measured from the flat state.
Sheet metal outside setback
Calculates OSSB = (Ri + t) × tan(θ/2) for two outside flanges.
Sheet metal bend deduction
Calculates BA, OSSB, and BD = 2 × OSSB - BA for one bend line.
Flat length from outside flanges
Calculates L_flat = A + B - BD for one bend and outside flange dimensions.
Flat length from tangent lengths
Calculates L_flat = L_tangent_1 + L_tangent_2 + BA without mixing outside flange dimensions.
K-factor from measured BA
Solves K = (BA/θ_rad - Ri) / t from a measured bend allowance.
V-die bending force estimate
Estimates F = k_b × σ × L × t² / V with an explicit user process coefficient.
Round hole punching force
Calculates perimeter πd and force F = perimeter × t × τ_s for round punching or piercing.
Rectangular punching force
Calculates perimeter 2(a + b) and force F = perimeter × t × τ_s for a rectangular contour.
Minimum bend radius from factor
Calculates minimum inside radius as user-supplied material factor times sheet thickness.
Measured springback
Describes measured springback from loaded and released angles; it does not predict material behavior.
Injection molding clamp force
Calculates clamp force from projected area, cavity pressure, and user-supplied safety factor.
Injection molding slab cooling time
Estimates cooling time with a simplified one-dimensional slab model and checks the logarithm domain.
Welding linear heat input
Calculates P = U I and net linear heat input H = η U I / v with inverse modes for H, U, I, v, and η.
Fillet weld volume and mass
Calculates cross-section area, volume, deposited mass, and required filler mass for an equal-leg fillet weld.
Welding time from deposition rate
Calculates welding time from required filler mass and user-supplied deposition rate.
Shielding gas consumption
Calculates shielding gas volume from gas flow rate and welding time.
Simple weld pass count
Divides required filler area by deposited area per pass and returns both continuous and rounded-up pass count.
Material roll length and mass
Calculates length, outer diameter, turn count, and mass from the winding volume equation.
Scale 4-20 mA signal to value
Converts a nominal 4-20 mA current signal to a process value over a minimum-maximum range.
Scale 0-10 V signal to value
Converts a nominal 0-10 V voltage signal to a process value over a minimum-maximum range.
Scale value to 4-20 mA
Converts a process value to a nominal 4-20 mA signal over a minimum-maximum range.
Scale value to 0-10 V
Converts a process value to a nominal 0-10 V signal over a minimum-maximum range.
Scale 0-20 mA signal to value
Converts a nominal 0-20 mA current signal to a process value over a minimum-maximum range.
Analog signal percent of range
Calculates signal position relative to a supplied range; values outside the nominal range are not blocked.
ADC voltage from counts
Calculates ADC input voltage from counts, bit resolution, and reference voltage.
ADC voltage resolution
Calculates the smallest ADC voltage step from reference voltage and bit count.
Measurement error percent
Calculates signed percent error from measured value and true value.
Encoder angle resolution
Calculates helper encoder angle resolution in degrees per pulse.
Encoder linear resolution
Calculates counts per output revolution and linear travel per count for a wheel diameter.
First-order response value
Calculates the exponential response value of a first-order process for a given time and time constant.
Time constant from the 63.2% point
Uses the practical approximation that the time to reach 63.2% of the response is the time constant tau.
Control gain
Calculates simple gain as output change divided by input change.
Simple parallel PID output
Calculates a helper parallel-form PID output from the supplied error terms.
ki from integral time
Calculates helper integral gain ki from kp and integral time.
kd from derivative time
Calculates helper derivative gain kd from kp and derivative time.
Overshoot from damping ratio
Estimates helper percent overshoot of a second-order system from damping ratio.
Second-order settling time
Estimates helper second-order settling time from damping ratio and natural frequency.
Ziegler-Nichols closed-loop tuning
Calculates indicative P, PI or PID settings from the closed-loop method using Ku and Pu.
Second-order parameters from overshoot and peak time
Calculates zeta and natural frequency from fractional overshoot and first peak time.
Sensor sensitivity
Calculates sensitivity as output signal change divided by input change.
Simple PT100 RTD temperature
Calculates temperature from RTD resistance using a simplified linear PT100 model.
Sensor span
Calculates span as upper range value minus lower range value.
Sensor accuracy percent of span
Calculates helper absolute error from accuracy given as percent of span.
Load cell force from mV/V
Calculates helper force from an mV/V signal using supplied rated signal and rated force.
Synchronous speed from frequency and poles
Calculates motor synchronous speed from supply frequency and pole count.
Motor slip speed
Calculates slip speed as synchronous speed minus rotor speed.
VFD frequency from speed
Calculates VFD command frequency from synchronous speed and pole count.
Stepper steps per mm
Calculates helper steps per millimeter from motor steps, microsteps, and screw lead.
Ball screw linear force from torque
Calculates helper idealized ball screw linear force from torque, efficiency, and lead.
Reflected inertia through gearbox
Calculates helper load inertia reflected through the square of the gear ratio.
Servo reflected inertia
Calculates load inertia reflected through gear ratio and the ratio to motor inertia.
Servo RMS torque
Calculates RMS torque from torque and segment-time arrays of the same length.
Motion required torque
Adds acceleration torque, load torque and friction torque for a simple axis balance.
Simple pneumatic cylinder force
Calculates ideal pneumatic cylinder force from pressure and effective area.
Pneumatic air volume per stroke
Calculates geometric air volume per stroke from piston area and stroke length.
Simple pneumatic cycle time
Calculates helper travel time for a given stroke at constant speed.
Air flow from air changes per hour
Calculates air flow from air changes per hour and room volume.
ACH from air flow
Calculates air changes per hour from air flow and room volume.
Fan power from flow and pressure rise
Calculates auxiliary fan power from volumetric flow rate, pressure rise, and efficiency.
Simple absolute humidity
Calculates auxiliary absolute humidity from water vapor pressure and temperature without climate tables.
Air heating power from flow and delta T
Estimates air heating power from volumetric flow rate and temperature difference.
Water heating power from flow and delta T
Estimates water heating power from volumetric flow rate and temperature difference.
Ventilation heat loss
Calculates a helper sensible heat-loss estimate for an air stream from density, specific heat, flow rate and temperature difference.
Humid air enthalpy
Calculates a helper simplified humid-air enthalpy from dry-bulb temperature and humidity ratio.
Air cooling power from flow and delta T
Estimates sensible air cooling power from volumetric flow rate and temperature difference.
Magnus dew point
Calculates a helper dew-point estimate for humid air from temperature and relative humidity; it does not replace HVAC condition validation.
Humidity ratio from temperature and RH
Calculates humidity ratio from temperature, relative humidity, and atmospheric pressure using the Magnus approximation.
Stull wet-bulb temperature
Estimates wet-bulb temperature with the empirical Stull equation over its limited temperature and RH range.
Two-stream moist-air mixing
Mixes two dry-air streams by humidity-ratio and moist-air enthalpy balances.
Cooling water flow rate from power
Calculates cooling-water volumetric flow from power, density, specific heat, and temperature difference.
Total cooling load from sensible and latent load
Sums sensible and latent cooling load without automatic equipment sizing.
Condensate rate from humidity-ratio difference
Calculates condensate mass flow from dry-air mass flow and humidity-ratio decrease.
Cooling energy from power and time
Calculates cooling energy from cooling power and time using the same relation as the thermal calculator.
Wall heat loss from U-value
Estimates heat loss through a wall from U-value, area, and temperature difference.
Required flat insulation thickness
Calculates required flat insulation thickness from conductivity, area, temperature difference, and allowed heat loss.
Pipe insulation heat loss
Calculates heat loss through a cylindrical pipe insulation layer using a simplified radial-conduction model.
Wall internal surface temperature
Calculates internal surface temperature from indoor temperature, heat flux, and internal surface resistance.
Condensation temperature margin
Calculates the difference between surface temperature and dew-point temperature without automatic building-compliance assessment.
Heat-loss energy through partition
Calculates heat-loss energy through a partition from U-value, area, temperature difference, and time.
Duct air velocity
Calculates duct air velocity from volumetric flow rate and cross-sectional area.
Duct area from flow and velocity
Calculates duct cross-sectional area from volumetric flow rate and air velocity.
Rectangular duct equivalent diameter
Calculates a helper equivalent diameter for a rectangular duct from its side lengths, without HVAC equipment selection.
Room volume
Calculates room volume from length, width, and height.
Room air change time
Calculates one air-change time from room volume and air flow.
Occupancy ventilation flow
Calculates air flow from occupant count and flow per person.
Room heat load from area
Estimates room heat load from floor area and a user-provided load index.
Room cooling load from area
Estimates room cooling load from floor area and a user-provided load index.
Room occupant sensible heat
Calculates occupant sensible heat from occupant count and sensible heat per person.
Room occupant latent heat
Calculates occupant latent heat from occupant count and latent heat per person.
Room total internal heat gain
Sums heat gains from occupants, lighting, and equipment.
Mass percent concentration
Calculates the solute mass fraction in a solution as mass percent.
Molar concentration
Calculates molar concentration from amount of substance and solution volume.
Mass concentration
Calculates mass concentration as solute mass divided by solution volume.
Volume percent concentration
Calculates component volume fraction in the total volume.
Mass ppm concentration
Calculates ppm as component mass divided by total mass and multiplied by 1,000,000.
Molar concentration from mass
Calculates molar concentration from solute mass, molar mass, and solution volume.
pH from [H+] concentration
Calculates pH as −log10([H+]) in the dilute-solution model.
[H+] concentration from pH
Calculates [H+] as 10^(−pH) in the dilute-solution model.
pOH from [OH−] concentration
Calculates pOH as −log10([OH−]) in the dilute-solution model.
[OH−] concentration from pOH
Calculates [OH−] as 10^(−pOH) in the dilute-solution model.
pH and pOH from pKw
Uses pH + pOH = pKw with editable pKw.
KA and pKa
Converts the acid dissociation constant and its negative decimal logarithm.
KB and pKb
Converts the base dissociation constant and its negative decimal logarithm.
Henderson–Hasselbalch equation
Calculates an acidic buffer pH from pKa and [A−]/[HA].
Basic acidic buffer
Calculates HA/A− buffer pH from Ka and both form concentrations.
Basic alkaline buffer
Calculates B/BH+ buffer pOH and pH from Kb, pKw, and both form concentrations.
Dilution C1V1 = C2V2
Calculates a simple solution dilution from conservation of concentration times volume.
Moles from mass and molar mass
Calculates amount of substance from mass and molar mass.
Mass from moles and molar mass
Calculates mass from amount of substance and molar mass.
Mole fraction
Calculates helper mole fraction from user-provided component moles and total moles.
Molality
Calculates molality as moles of solute per kilogram of solvent.
Normality with manual equivalent factor
Calculates normality from molarity and a manually supplied equivalent factor.
Equivalent mass
Calculates equivalent mass in g/eq or kg/eq from molar mass and a manually supplied equivalent factor.
Serial dilution
Calculates the overall factor and concentration after a whole number of repeated dilution stages.
Minimum dilution-stage count
Calculates the smallest whole number of stages required to reach a concentration no greater than the target.
Basic stoichiometric titration
Calculates C2 from C1·V1·n1 = C2·V2·n2.
Cell potential from half-cells
Calculates cell potential as cathode reduction potential minus anode reduction potential.
Nernst equation
Calculates potential from E⁰, absolute temperature T, electron count z, and quotient Q.
ΔG and cell potential
Calculates ΔG = −zFE.
Faraday's law
Calculates Q = n·z·F from amount of substance n and electron count z per entity.
Electrolysis deposited mass
Calculates mass from I, t, M, z, and current efficiency.
Electrolysis time
Calculates time required to deposit the specified mass.
Required electrolysis current
Calculates current for a specified mass and time.
Amount of substance from charge
Calculates amount of substance from charge Q and electron count z.
Beer–Lambert law
Calculates absorbance A from molar absorptivity ε, optical path length l, and molar concentration c.
Osmotic pressure
Calculates osmotic pressure from the van ’t Hoff equation for an ideal dilute solution.
Simple Raoult law
Calculates solvent partial pressure as its mole fraction times the pure-solvent vapour pressure.
Freezing-point depression
Calculates freezing-point depression from molality, the cryoscopic constant, and the van ’t Hoff factor.
Boiling-point elevation
Calculates boiling-point elevation from molality, the ebullioscopic constant, and the van ’t Hoff factor.
Water hardness conversion
Converts water hardness through the mg/L as CaCO3 base representation.
Hardness from Ca and Mg
Calculates hardness as CaCO3 from calcium and magnesium concentrations.
TDS from conductivity
Calculates TDS from EC and a manually supplied k_TDS factor.
Hydraulic retention time
Calculates HRT = V/Q for a tank or basin.
Pollutant load
Calculates mass load from flow rate and concentration using canonical units.
Tank volume from Q and HRT
Calculates required volume from flow rate and retention time.
Removal efficiency
Calculates percent removal from C_in and C_out.
Water stream mixing
Calculates mixed concentration as a flow-weighted average for a list of streams.
Component mass fraction
Calculates a component mass fraction from component mass and total mass.
Simple mixture density
Calculates average mixture density from total mass and total volume.
Component mass from mass fraction
Calculates component mass from mass fraction and total mixture mass.
Total mass from component fraction
Calculates total mass from component mass and its mass fraction.
Weighted two-component mixture property
Calculates a linear approximation of a user-provided mixture property from two component masses and properties.
Component volume from volume fraction
Calculates component volume from volume fraction and total volume.
Molar flow rate
Calculates molar flow from mass flow and molar mass.
Two-stream mixer mass balance
Calculates helper output mass flow as the sum of two user-provided streams.
Mixed concentration of two streams
Calculates helper mixed concentration as a flow-weighted average from user-provided values.
Residence time
Calculates helper residence time as volume divided by volumetric flow rate.
Reactor conversion
Calculates helper conversion from user-provided inlet and outlet moles.
First-order half-life
Calculates helper first-order half-life from a user-provided rate constant.
Arrhenius rate constant
Calculates helper rate constant from the Arrhenius equation using user-provided values.
CSTR first-order volume
Calculates ideal CSTR volume for a first-order reaction, constant density and supplied conversion.
PFR first-order volume
Calculates ideal PFR volume for a first-order reaction, constant density and supplied conversion.
Agitator power from power number
Calculates agitator power from power number, density, rotational speed in 1/s and impeller diameter.
Tank drain time by Torricelli
Calculates the time for liquid head to drop from initial to final height for a constant tank area.
Ideal gas moles
Calculates amount of substance from pressure, volume, temperature, and the universal gas constant.
Ideal gas density
Calculates ideal-gas density from pressure, molar mass, and temperature.
Gas molar volume
Calculates ideal-gas molar volume from temperature, pressure, and the gas constant.
Gas mass from moles and molar mass
Calculates gas mass from amount of substance and user-entered molar mass.
Partial pressure
Calculates helper partial pressure from user-provided mole fraction and total pressure.
Stoichiometric moles from reaction ratio
Calculates product moles from reactant moles and user-entered stoichiometric coefficients.
Simple limiting reactant
Compares available reaction extent for two components from entered moles and coefficients.
Limiting and excess reactant
Compares two reactant amounts divided by stoichiometric coefficients and reports the limiting reactant, remainder, and excess.
Theoretical yield mass
Calculates theoretical product mass from moles and user-entered molar mass.
Percent yield
Calculates percent yield from actual and theoretical product mass.
Annual building energy demand
Calculates annual building energy demand from reference floor area and specific indicators for space heating, space cooling, domestic hot water, and other uses.
Energy cost from kWh and price
Calculates energy cost from energy in kWh and price per kWh.
Simple payback period
Calculates helper payback period from user-provided investment cost and annual savings.
Simple wind turbine power
Simple estimate calculator for wind power from air density, swept area, wind speed, and power coefficient.
Wind capacity factor
Simple estimate calculator for capacity factor from actual energy, rated power, and time.
Hydro power from head and flow
Simple estimate calculator for hydro power from density, gravity, flow rate, head, and efficiency.
CO2 emission from energy
Simple estimate calculator for CO2 emission from energy and a user-provided emission factor.
Energy savings
Simple estimate calculator for energy savings as baseline energy minus new energy.
Energy savings percent
Simple estimate calculator for percent energy savings relative to baseline energy.
Simple LCOE
Simple estimate calculator for unit energy cost from total lifetime cost and lifetime energy.
Simple efficiency
Simple estimate calculator for efficiency as useful output divided by input.
PV power from area and efficiency
Estimates PV power from module area, irradiance, and efficiency.
Simple PV daily energy
Estimates daily PV energy from peak power, sun hours, and performance ratio.
PV module count from power
Calculates the minimum whole number of PV modules required to meet the target power.
Solar thermal collector power
Simple estimate calculator for solar thermal collector power from area, irradiance, and efficiency.
PV string series count with temperature
Calculates temperature-corrected Voc/Vmp and module-count limits from DC voltage and MPPT range.
PV inverter power sizing
Calculates required AC apparent power and recommended inverter power from active power, power factor and loading fraction.
Battery storage energy from voltage and Ah
Estimates storage energy from nominal voltage and amp-hour capacity.
Battery runtime from energy and power
Estimates storage runtime from available energy and load power.
Battery usable energy
Calculates helper usable energy from user-provided nominal energy, depth of discharge, and efficiency.
Battery C-rate
Simple estimate calculator for C-rate from user-provided current and Ah capacity.
Battery charge time
Simple estimate calculator for charge time from user-provided Ah capacity and charging current.
Battery capacity for autonomy
Calculates required load energy, nominal battery energy and Ah capacity for a target autonomy time.
Heat pump COP
Calculates heat pump COP as heat output divided by electric power.
Heat pump electric power
Calculates heat pump electric power from heat output and COP.
Heat pump water flow rate
Calculates helper volumetric flow from user-provided heat power and fluid properties.
Carnot heat pump COP for heating
Simple estimate calculator for ideal Carnot COP in heating mode from user-provided absolute temperatures.
Fuel energy from mass and LHV
Calculates fuel chemical energy from mass and user-provided lower heating value.
Fuel CO2 emission
Simple estimate calculator for CO2 emission from fuel mass and a user-provided emission factor.
Useful heat from fuel and efficiency
Calculates useful heat from fuel mass, user-provided LHV, and efficiency.
Fuel mass from required heat
Calculates fuel mass from required useful heat, LHV, and efficiency provided by the user.
Fuel cost from mass
Calculates fuel cost from mass and price per mass in the same notional currency.
Fuel volumetric energy density
Calculates volumetric energy density from user-provided LHV and fuel density.
Cp process capability
Calculates the Cp capability index from specification limits and process standard deviation.
Cpk process capability
Calculates the Cpk capability index from specification limits, mean, and standard deviation. Cpk can be negative when the mean is outside tolerance.
Simple process sigma level
Calculates an approximate sigma level as spec limit distance divided by standard deviation.
Scrap rate
Calculates scrap percentage from scrap count and total count.
Yield rate
Calculates yield percentage from good count and total count.
First pass yield
Calculates FPY from good first-pass units and total units as an auxiliary quality metric.
Rolled throughput yield
Multiplies three process-step yields to estimate overall RTY as an auxiliary quality metric.
Rework rate
Calculates the percentage of units requiring rework as an auxiliary quality metric.
DPMO
Calculates defects per million opportunities from defects, units, and opportunities per unit.
PPM defects
Calculates defects per million units as an auxiliary quality metric.
Xbar control limits
Calculates the existing sigma-based Xbar limits and Xbar-R chart limits from the grand mean and average range.
p-chart control limits
Calculates basic p-chart limits from pBar and sample size without creating an SPC chart.
np-chart control limits
Calculates basic np-chart limits from pBar and sample size without automatic process assessment.
c-chart control limits
Calculates basic c-chart limits for an average count of nonconformities.
u-chart control limits
Calculates basic u-chart limits from uBar and sample size.
OEE
Calculates OEE from availability, performance, and quality percentages.
Availability rate
Calculates OEE availability from operating time and planned production time.
OEE quality rate
Calculates the OEE quality component from good count and total count.
Tolerance stack worst case
Sums three tolerance contributors in a simple worst-case stack.
Tolerance stack RSS
Calculates total tolerance as the root sum square of three contributors.
Bilateral limits from nominal tolerance
Finds upper and lower limits for a symmetric bilateral tolerance.
Unilateral upper limit
Calculates the upper limit from a nominal value and positive upper tolerance.
Unilateral lower limit
Calculates the lower limit from a nominal value and signed lower tolerance.
Clearance from hole and shaft
Calculates signed clearance as hole diameter minus shaft diameter.
Expanded uncertainty
Multiplies standard uncertainty by a coverage factor.
Measurement result with uncertainty limits
Finds lower and upper limits of a measurement result from a given uncertainty.
Thin lens
Calculates 1/f = 1/d_o + 1/d_i and image classification for a thin lens.
Magnification and image height
Calculates m = -d_i/d_o and h_i = m*h_o.
Optical power
Calculates optical power P = 1/f with focal length in metres.
Snell's law
Solves n1*sin(theta1) = n2*sin(theta2) with arcsine-domain checks.
Critical angle
Calculates theta_c = asin(n2/n1) only for n1 > n2.
Brewster angle
Calculates theta_B = atan(n2/n1) for light incident from medium n1 to n2.
Spherical mirror
Calculates the mirror equation 1/f = 1/d_o + 1/d_i and R = 2f.
Rayleigh resolution
Calculates theta_min = 1.22*lambda/D and small-angle s = L*theta_min for a circular aperture.
Wave equation
Solves v = f*lambda and returns period, angular frequency, and wave number.
Doppler effect
Calculates f_obs = f_src*(v + s_o*v_o)/(v - s_s*v_s) for a stationary medium.
Beats
Calculates beat frequency f_beat = |f1 - f2|.
Standing wave on a string
Calculates speed v = sqrt(Tension/mu_L) and harmonic frequency f_n = n*v/(2L).
Sound pressure level
Calculates SPL = 20*log10(p_rms/p_ref) and inverse p_rms = p_ref*10^(SPL/20).
Sound intensity level
Calculates L_I = 10*log10(I/I_ref), by default relative to 10^-12 W/m².
Sound level summation
Sums a list of levels L_total = 10*log10(sum(10^(L_i/10))) with a 128-value limit.
Geometric spreading
Calculates free-field point-source level drop: L2 = L1 - 20*log10(r2/r1).
Sabine reverberation time
Calculates T60 = 0.161*V/A_eq and A_eq from surface and absorption-coefficient lists.
Acoustic impedance
Calculates plane-wave characteristic acoustic impedance Z = rho*c.
Percentage of value
Calculates the part, percent, or whole from part = percent * whole / 100.
Percentage change
Calculates percentage change, old value, or new value.
Ratio from two values
Calculates the ratio a / b or the missing value from a simple quotient.
Average of two numbers
Calculates the arithmetic average of two numbers or the missing number.
Proportion solver
Solves the missing value in the proportion a / b = c / d.
Unit rate
Calculates unit rate, quantity, or time from rate = quantity / time.
Decimal and common fraction converter
Converts a finite decimal notation to a reduced common fraction and calculates a fraction's decimal value.
Fractional and decimal inches converter
Rounds a length to the nearest standard inch fraction and reports the rounding error.
Power calculator
Calculates the power result, base, or exponent.
Root calculator
Calculates the root, original value, or root degree.
Logarithm calculator
Calculates the logarithm, value, or logarithm base.
Arithmetic sequence nth term
Calculates the nth term, first term, common difference, or term number of an arithmetic sequence.
Geometric sequence nth term
Calculates the nth term, first term, ratio, or term number of a geometric sequence.
Direct variation
Calculates y, coefficient, or x from y = k * x.
Inverse variation
Calculates y, coefficient, or x from y = k / x.
Linear interpolation
Calculates y between two points using linear interpolation.
Bilinear interpolation
Calculates a value inside a rectangle from four corner values using bilinear interpolation.
2x2 linear system
Solves a simple system of two linear equations with two unknowns.
3D vector magnitude
Calculates the magnitude of a 3D vector from three components.
3D vector dot product
Calculates the dot product of two 3D vectors.
Angle between 3D vectors
Calculates the angle between two non-zero 3D vectors.
Trapezoidal integration from three points
Calculates a simple trapezoidal-rule integral for three equally spaced points.
Degrees to radians
Converts an angle from degrees to radians and back.
Radians to degrees
Converts an angle from radians to degrees.
Sine in a right triangle
Calculates sine, the opposite side, the hypotenuse, or the angle.
Cosine in a right triangle
Calculates cosine, the adjacent side, the hypotenuse, or the angle.
Tangent in a right triangle
Calculates tangent, the opposite side, the adjacent side, or the angle.
Triangle area from two sides and angle
Calculates area, side a, side b, or included angle from area = 0.5 * a * b * sin(C).
Law of sines
Calculates a side or angle from a / sin(A) = b / sin(B).
Law of cosines
Calculates side c or angle C from c² = a² + b² - 2ab cos(C).
Z-score
Calculates z-score, value, mean, or standard deviation.
Variance from standard deviation
Calculates variance or standard deviation from variance = standardDeviation^2.
Standard deviation from variance
Calculates standard deviation from variance.
Coefficient of variation
Calculates coefficient of variation, standard deviation, or mean.
Standard error
Calculates standard error, standard deviation, or sample size.
Normal margin of error
Calculates margin of error, z-score, standard deviation, or sample size.
Mean confidence interval
Calculates the margin and lower and upper mean interval limits from a supplied z value.
RMS of three values
Calculates the root mean square of three supplied values.
Weighted average
Calculates a simple weighted average from three values and three weights.
Probability complement
Calculates complement probability or probability.
Odds from probability
Calculates odds or probability from odds = p / (1 - p).
Probability from odds
Calculates probability from non-negative odds.
Linear equation ax + b = 0
Calculates the solution, coefficient a, or coefficient b for ax + b = 0.
Linear equation ax + b = c
Calculates the solution or one component of ax + b = c.
Quadratic equation real roots
Calculates the discriminant and two real roots of ax^2 + bx + c = 0.
2x2 linear system
Solves a 2x2 linear system using Cramer's rule.
Basic exponential equation
Calculates the solution or one parameter of a * b^x = c.
Length converter
Converts length between units registered in the project.
Area converter
Converts area between units registered in the project.
Volume converter
Converts volume between units registered in the project.
Mass converter
Converts mass between units registered in the project.
Force converter
Converts force between units registered in the project.
Pressure converter
Converts pressure between units registered in the project.
Torque converter
Converts torque between units registered in the project.
Energy converter
Converts energy between units registered in the project.
Power converter
Converts power between units registered in the project.
Speed converter
Converts speed between units registered in the project.
Acceleration converter
Converts acceleration between units registered in the project.
Temperature converter
Converts temperature between units registered in the project.
Density converter
Converts density between units registered in the project.
Volumetric flow converter
Converts volumetric flow between units registered in the project.
Dynamic viscosity converter
Converts dynamic viscosity between units registered in the project.
Kinematic viscosity converter
Converts kinematic viscosity between units registered in the project.
Time converter
Converts time between units registered in the project.
Angle converter
Converts angles between units registered in the project.
Frequency converter
Converts frequency between units registered in the project.
Mass flow converter
Converts mass flow between units registered in the project.
Electric charge converter
Converts electric charge between units registered in the project.
Voltage converter
Converts voltage between units registered in the project.
Electric current converter
Converts electric current between units registered in the project.
Resistance converter
Converts resistance between units registered in the project.
Capacitance converter
Converts capacitance between units registered in the project.
Inductance converter
Converts inductance between units registered in the project.
Amount of substance converter
Converts only amount-of-substance units, without calculating moles from a chemical formula.
Angular acceleration converter
Converts angular acceleration units; it does not derive acceleration from rotational motion.
Apparent power converter
Converts apparent power S units; it does not mix them with active or reactive power.
Electrical conductivity converter
Converts electrical conductivity sigma units; it does not convert them to conductance or resistance.
Current density converter
Converts current density J units; it does not calculate density without current and area.
Cutting speed converter
Converts cutting speed units; it does not calculate speed from diameter and spindle speed.
Feed rate converter
Converts feed-rate units; it does not mix feed per revolution or feed per tooth.
Heat transfer coefficient converter
Converts heat transfer coefficient h units; it is not a material thermal conductivity converter.
Magnetic field strength converter
Converts magnetic field strength H units; it does not mix them with tesla or weber.
Magnetic flux converter
Converts magnetic flux Phi units; it does not convert flux density.
Magnetic flux density converter
Converts magnetic flux density B units; it does not mix them with flux or field strength.
Mass concentration converter
Converts mass concentration units; it does not calculate concentration from sample mass and volume.
Mass moment of inertia converter
Converts mass moment of inertia units; it does not calculate inertia from geometry and mass.
Molar concentration converter
Converts molar concentration units; it does not require or use molar mass.
Molar mass converter
Converts molar mass units; it does not derive molar mass from chemical composition.
Reactive power converter
Converts reactive power Q units; it does not mix them with watts or volt-amperes.
Resistivity converter
Converts resistivity rho units; it does not calculate wire resistance without length and area.
Angular velocity converter
Converts angular velocity units; it is not a plain angle converter.
Second moment of area converter
Converts second moment of area I units; it does not calculate section geometry.
Section modulus converter
Converts section modulus W units; it does not calculate it from section geometry.
Specific heat capacity converter
Converts specific heat capacity units; it does not derive heat capacity from energy, mass and temperature change.
Spring rate converter
Converts spring rate units; it does not calculate spring force or deflection.
Stiffness converter
Converts linear stiffness units; it does not mix them with surface tension.
Surface tension converter
Converts surface tension units; it is not a spring stiffness converter.
Thermal conductivity converter
Converts thermal conductivity lambda/k units; it is not a heat transfer coefficient converter.
Electrical conductance converter
Converts electrical conductance G units in siemens; it does not calculate reciprocal resistance or material conductivity.
Damping coefficient converter
Converts linear damping coefficient c units; it does not calculate damping force, critical damping or stiffness.
Specific latent heat converter
Converts phase-change heat per mass units; it does not calculate energy from mass or mix them with specific heat capacity.
Stress intensity factor converter
Converts K = stress times square-root length units; it does not calculate KI, KIC, crack geometry or material toughness.
Thermal diffusivity converter
Converts thermal diffusivity alpha units; it does not derive it from conductivity, density and heat capacity.
Thermal expansion coefficient converter
Converts linear thermal expansion coefficient units; it does not calculate elongation, thermal stress or temperature.
Thermal resistance converter
Converts thermal resistance Rth units; it does not calculate it from geometry, area or heat transfer coefficient.
Electric field strength converter
Converts electric field strength E units; it does not calculate field from voltage and distance, electrode geometry or dielectric breakdown.
Illuminance converter
Converts illuminance units; it does not size luminaires, calculate room lighting, luminance or standard compliance.
Specific volume converter
Converts specific volume units; it does not calculate reciprocal density, ideal-gas state, temperature or pressure.
Rectangle perimeter
Calculates rectangle perimeter from width and height.
Triangle area from base and height
Calculates triangle area from base and height.
Triangle area by Heron's formula
Calculates semi-perimeter and triangle area from three sides.
Arc length
Calculates arc length from radius and angle after converting the angle to radians.
Circle sector area
Calculates circle sector area from radius and angle in radians.
Circle segment area
Calculates circular segment area from radius and central angle in radians.
Regular polygon area
Calculates regular polygon area from side count and side length.
Hexagon area
Calculates regular hexagon area from side length.
Slot area
Calculates obround slot area from straight length and width.
Bolt circle chord length
Calculates the chord distance between adjacent holes on a bolt circle.
Simple sheet metal flat length
Simple flat length calculator from two flanges and bend allowance.
Chamfer length from offsets
Calculates chamfer length from two perpendicular offsets.
Cube volume
Calculates cube volume from side length.
Cuboid volume
Calculates cuboid volume from length, width, and height.
Cone frustum volume
Calculates cone frustum volume from two radii and height.
Cone frustum lateral surface area
Calculates cone frustum lateral surface area from two radii and height.
Horizontal cylindrical tank volume
Calculates liquid volume in a straight horizontal cylinder from fill height and circular-segment area.
Rectangular second moment of area
Calculates Ix and Iy for a rectangular section.
Circular second moment of area
Calculates second moment of area for a solid circular section.
Hollow circular second moment of area
Calculates second moment of area for a hollow circular section.
Rectangular section modulus
Calculates rectangular section modulus about the x-axis.
Circular section modulus
Calculates section modulus for a solid circular section.
Parallel axis theorem for area
Transfers a centroidal second moment of area to a parallel axis.
Principal area moments
Calculates principal second moments of area and the principal axis angle from Ix, Iy, and Ixy.
RHS/SHS section properties
Calculates area, centroid, second moments, directional section moduli, and mass per length for an RHS or SHS profile.
CHS and pipe section properties
Calculates area, second moments, section moduli, and mass per length for a pipe or CHS from outer diameter and wall thickness.
Lipped channel section properties
Calculates geometric properties and mass per length for a lipped channel from five non-overlapping rectangles.
I-section properties
Calculates area, centroid, and area moments for an I-section modeled with rectangles.
Channel section properties
Calculates channel-section properties from a rectangular web and two flanges.
Angle section properties
Calculates angle-section properties as two rectangles with the overlapped corner subtracted.
T-section properties
Calculates T-section properties from a rectangular flange and web.
Z-section properties
Calculates Z-section properties with flanges placed on opposite sides of the web.
2D distance
Calculates the distance between two points in a plane.
2D midpoint
Calculates midpoint coordinates between two points.
2D slope
Calculates the slope of a line through two points.
Bolt circle coordinates
Calculates x and y coordinates for a bolt-circle hole from radius, hole count, index, and start angle.
Advanced bolted-joint analysis
Analysis of a single bolt or identical parallel bolts in a preloaded joint, including stiffnesses, separation, stresses and Goodman utilization.
Advanced PCB designer
Interactive stack-up, trace-segment and via-group designer with resistance, voltage drop, power loss and user-defined limits.
Antenna and waveguide suite
Three-tab RF suite for rectangular waveguides, dipoles with link budget, and rectangular patch antennas with visualization and JSON export.
Cable and feeder sizing designer
Manual verification of a selected cable and feeder: Ib, corrected Iz, protective device, voltage drop and explicit margins without normative tables.
Circuit Analysis Solver
Local MNA solver for linear DC and AC circuits with RLC elements, independent and controlled sources, phasors, complex power and frequency sweeps.
Preliminary base plate analysis
Preliminary rectangular base plate analysis: pressure map from N, Mx and My, cantilever thickness and anchor force distribution.
Full beam solver
Euler-Bernoulli finite element beam solver for supports, point loads and distributed loads.
Chemical equation balancer
Exact atom balancing with the smallest whole-number stoichiometric coefficients.
Chemical formula parser
Element composition, atom-count and molar-mass analysis for formulae with groups and hydrates.
2D frame solver
Linear Euler-Bernoulli plane-frame FEM solver with three-DOF nodes, supports, nodal loads and local member distributed loads.
Lifting lug analysis
Simplified analysis of a flat lifting lug with net tension, hole bearing, shear-out, base section and pin checks.
Preliminary retaining wall check
Preliminary cantilever retaining-wall analysis per 1 m length: Rankine or user Ka pressure, water, uplift, passive resistance, sliding, overturning, contact and base bearing pressures.
RF transmission line designer
RF line design and analysis for coax, quasi-TEM microstrip, RLGC propagation, load transformation, quarter-wave matching and frequency sweep.
Full psychrometrics
Moist-air properties with the Buck equation: RH, W, dew point, wet bulb, vapor pressure, enthalpy, density, comparison and air-stream mixing.
Interactive psychrometric chart
Tdb-W chart with saturation boundary, RH curves, enthalpy and specific-volume lines, state points and HVAC processes.
Pipe network solver
Steady node-link network solver for incompressible liquid flow with pipes, minor losses, pumps, and known-head or known-pressure boundary nodes.
Speaker enclosure designer
Interactive sealed and bass-reflex enclosure designer with Thiele-Small parameters, net and gross volume, ports, impedance model, excursion, SPL, user limits, import and export.
IAPWS-IF97 steam tables
Pure water and steam properties from IAPWS-IF97 equations for Regions 1-5, saturation, quality, inverse solvers, tables and charts.
Thermodynamic cycle analyzer
Interactive state, heat/work balance, power and efficiency analyzer for Otto, Diesel, Brayton, simple Rankine and reheat Rankine cycles.
Profile and section comparator
Active tool for comparing profiles from geometry, Section Builder imports or manually entered properties with a shared load case, mass, W, My, Mallow, Fallow and mass-normalized indicators.
Rectangular reinforced-concrete beam analysis
Rectangular reinforced-concrete beam section analysis with force equilibrium, reinforcement layers, user stress block, cracking and shear checks from user-provided capacity.
Shallow foundation analyzer
Preliminary rectangular shallow-foundation analysis with biaxial eccentricity, tensionless contact, uplift, bearing capacity, sliding and elastic settlement from user-defined limits.
Bolt group analysis
Elastic shear and tension distribution in an arbitrary bolt group with optional utilization checks from user-provided capacities.
Interactive section builder
Build composite sections from rectangles, circles, polygons and voids, then compute geometric section properties.
2D truss solver
Linear finite element solver for planar trusses with supports, nodal loads, reactions, displacements and axial member forces.
Mohr's circle with visualization
2D stress transformation, principal stresses, maximum shear and a calculation-driven Mohr-circle visualization.
Advanced LEFM fracture assessment
LEFM analysis with four documented geometries, KIC criterion and inverse allowable-stress and crack-length solutions.
Stress concentration library
Searchable library of four documented Kt correlations with validity enforcement and geometry diagrams.
Advanced fatigue crack growth
Numerical crack propagation for variable-amplitude load blocks with Paris, Walker and Forman models.
Wind, snow and seismic actions
Four calculation modules for wind, snow, seismic base shear and transparent action combinations, without automatic zone lookup.
Steel connection design
Modular bolt shear, plate bearing and fillet-weld checks with component resistances and a governing failure mode.
Reinforced concrete design suite
Two explicit simplified EN 1992-1-1 beam flexure and concrete-shear models plus a clearly limited linear N–M column-section screening check.
Geotechnical design suite
Transparent shallow-foundation bearing check with analytical capacity factors and user-supplied modifiers.
Sanitary system design
Two pipe-sizing modules: pressurized Hazen-Williams and gravity Manning with velocity, loss and utilization checks.
Material database
Curated real material properties with search, filtering, comparison, conditions and explicit data provenance.
Structural profiles database
IPE and HEA section database with dimensions, mass and section properties tied to an explicit series and source.
Fluid properties database
Condition-specific fluid properties from the open CoolProp library: density, viscosity, specific heat and thermal conductivity with temperature and pressure.
Refrigerant database
Pure-refrigerant database with CoolProp critical and saturation data plus EPA environmental values where available.
Safe CAS engine
Bounded symbolic algebra engine with a safe AST, exact arithmetic and explicit messages for unsupported cases.
General symbolic solving
Polynomial equation solving through degree four with exact results where available, complex approximations and verification.
Advanced equation systems
Linear systems up to 12 unknowns and controlled nonlinear systems up to 6 unknowns with residuals.
FEA mesh convergence analyzer
Multi-series analysis of result changes, trends, observed order and asymptote over successive FEA meshes.
FFT and spectrum analyzer
Multi-channel one-sided peak-amplitude spectra with windows, detrending, coherent-gain correction and largest-bin ranking.
Measurement uncertainty budget builder
Independent Type A/B budget with distributions, sensitivities, RSS, Welch–Satterthwaite and explicit k.