About this calculator
Calculate roof angle, rise-in-12 pitch and slope percentage.
Rise and run must use the same measurement unit.
Formula
Angle = arctan(rise ÷ run). Slope % = rise ÷ run × 100.
Example
Rise 6 over run 12 = 26.6° and 50% slope.
Accuracy
NUMTX shows the assumptions next to the calculation so you can replace defaults with values that match your situation. For measurements, supplier rates, fees, interest, tax or regulated work, confirm important figures with the appropriate official or professional source.