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Roof Pitch Calculator

Roof pitch, angle and slope multiplier from rise and run.

How it's calculated

Pitch is the rise per 12 inches of run: rise ÷ run × 12. Angle = arctan(rise ÷ run). The multiplier, √(1 + (pitch ÷ 12)²), converts flat footprint area into actual sloped roof area.

Example

6 inches of rise over 12 of run is a 6/12 pitch, 26.6°, with a 1.118 multiplier.

Common pitches

PitchAngleMultiplier
3/1214.0°1.031
4/1218.4°1.054
5/1222.6°1.083
6/1226.6°1.118
7/1230.3°1.158
8/1233.7°1.202
9/1236.9°1.250
10/1239.8°1.302
12/1245.0°1.414

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