Roof pitch calculator
Enter the rise and run to get your roof pitch, angle, and slope multiplier. Add your house footprint to estimate the actual roof area and squares.
Roof pitch
6/12
Roof angle
26.6°
Slope multiplier
1.118
Roof area
Add a footprint
Common roof pitches
| Pitch | Angle | Multiplier |
|---|---|---|
| 2/12 | 9.5° | 1.014 |
| 3/12 | 14° | 1.031 |
| 4/12 | 18.4° | 1.054 |
| 5/12 | 22.6° | 1.083 |
| 6/12 | 26.6° | 1.118 |
| 7/12 | 30.3° | 1.158 |
| 8/12 | 33.7° | 1.202 |
| 9/12 | 36.9° | 1.25 |
| 10/12 | 39.8° | 1.302 |
| 12/12 | 45° | 1.414 |
How it works
Pitch is the rise in inches for every 12 inches of horizontal run. The angle is arctan(rise ÷ run). The slope multiplier, √(1 + (rise ÷ run)²), converts a flat footprint into true roof surface area. One roofing square is 100 sq ft. Rise and run can be in any unit as long as both use the same one — pitch is a ratio, so inches and centimeters give the same result.
Results are estimates. Verify measurements on site before ordering materials.
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