Roof slope percent

Calculates roof pitch angle as arctangent of rise divided by run.

Calculates sloped roof area from plan area and roof angle plus required material area with waste.

Converts roof plan area into approximate sloped roof area using the pitch angle.

Helper calculation of geometric rafter length from run and rise; it is not code-based design.

Calculates stair slope angle from riser height and tread depth.

Calculates single riser height from total rise and riser count.