How this calculator works
Enter the values for value, rate (%) and review the units before calculating.
Formula / method
Pitch = rise:run; slope % = rise ÷ run × 100; angle = arctan(rise ÷ run)
Worked example
30 cm rise over 60 cm run is a 6:12 pitch, 50% slope and 26.565° angle.
Assumptions and limitations
Rise and run form a right triangle and are measured in the same units.
Roof framing, drainage, materials and local code requirements require professional confirmation.