🏠Roof Pitch Calculator
Turn rise and run (or an angle) into roof pitch, degrees, slope percent and an area multiplier.
Your roof
Your roof pitch is
6.0/12
26.57° · 50.0% slope · area multiplier 1.118
pitch
6.0/12
degrees
26.57
slope %
50.0
multiplier
1.118
Multiply your house footprint (plus overhangs) by the area multiplier to get the real roof surface area.
How it works
Pitch = rise ÷ run × 12 (written x/12). Angle = arctan(rise ÷ run). Slope % = rise ÷ run × 100. Roof area multiplier = √(1 + (rise ÷ run)²) — multiply your flat footprint by it to get real roof area.
Worked example
A rise of 6 in over a run of 12 in is a 6/12 pitch: 26.57°, 50% slope, and an area multiplier of 1.118.
Questions people ask
4/12 to 9/12 on most houses.
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Last updated October 8, 2026. These results are friendly estimates to help you plan — always double-check before buying or making big decisions.