Roof Pitch to Degrees: Chart and Converter
Switch between the x/12 pitch roofers use and the angle a saw, phone app or solar installer wants.
Pitch to degrees
Degrees to pitch
The conversion
Degrees = arctan(rise ÷ 12) e.g. arctan(7 ÷ 12) = 30.26°
Pitch = 12 × tan(degrees) e.g. 12 × tan(22.5°) = 4.97 → about 5/12
Your calculator needs to be in degree mode for the tan and arctan keys. On a spreadsheet, use =DEGREES(ATAN(B2/12)) and =12*TAN(RADIANS(C2)).
Full pitch to degrees chart
| Pitch | Angle | Multiplier | Slope % | Hip/valley factor |
|---|---|---|---|---|
| 1/12 | 4.76° | 1.0035 | 8.3% | 1.4167 |
| 2/12 | 9.46° | 1.0138 | 16.7% | 1.4240 |
| 3/12 | 14.04° | 1.0308 | 25.0% | 1.4361 |
| 4/12 | 18.43° | 1.0541 | 33.3% | 1.4530 |
| 5/12 | 22.62° | 1.0833 | 41.7% | 1.4743 |
| 6/12 | 26.57° | 1.1180 | 50.0% | 1.5000 |
| 7/12 | 30.26° | 1.1577 | 58.3% | 1.5298 |
| 8/12 | 33.69° | 1.2019 | 66.7% | 1.5635 |
| 9/12 | 36.87° | 1.2500 | 75.0% | 1.6008 |
| 10/12 | 39.81° | 1.3017 | 83.3% | 1.6415 |
| 11/12 | 42.51° | 1.3566 | 91.7% | 1.6853 |
| 12/12 | 45.00° | 1.4142 | 100.0% | 1.7321 |
| 13/12 | 47.29° | 1.4743 | 108.3% | 1.7815 |
| 14/12 | 49.40° | 1.5366 | 116.7% | 1.8333 |
| 15/12 | 51.34° | 1.6008 | 125.0% | 1.8875 |
| 16/12 | 53.13° | 1.6667 | 133.3% | 1.9437 |
| 17/12 | 54.78° | 1.7341 | 141.7% | 2.0017 |
| 18/12 | 56.31° | 1.8028 | 150.0% | 2.0616 |
| 19/12 | 57.72° | 1.8727 | 158.3% | 2.1230 |
| 20/12 | 59.04° | 1.9437 | 166.7% | 2.1858 |
| 21/12 | 60.26° | 2.0156 | 175.0% | 2.2500 |
| 22/12 | 61.39° | 2.0883 | 183.3% | 2.3154 |
| 23/12 | 62.45° | 2.1619 | 191.7% | 2.3819 |
| 24/12 | 63.43° | 2.2361 | 200.0% | 2.4495 |
Handy reference points
- 12/12 = 45°. Rise equals run. Anything steeper is more than 45°.
- About 7/12 ≈ 30° (exactly 30.26°). A true 30° roof is 6.93/12.
- About 3.2/12 ≈ 15°, and 2/12 ≈ 9.5°. Low-slope products start to matter around here.
- Degrees do not scale evenly with pitch: going from 1/12 to 2/12 adds 4.7°, while going from 23/12 to 24/12 adds about 1°.
Worked examples
Solar layout. A racking spec asks for the roof angle. The roof is 5/12: arctan(5 ÷ 12) = 22.62°.
Miter saw. To cut a rafter plumb cut on a 9/12 roof, set the saw to the roof angle, arctan(9 ÷ 12) = 36.87°.
Inclinometer reading. An app reads 18.4° on the shingles. 12 × tan(18.4°) = 3.99, so the roof is 4/12.
Frequently asked questions
How many degrees is a 4/12 roof pitch?
A 4/12 pitch is 18.43 degrees.
How many degrees is a 7/12 roof pitch?
A 7/12 pitch is 30.26 degrees, which is why 7/12 is often described as a 30-degree roof.
What pitch is a 45 degree roof?
A 45-degree roof is a 12/12 pitch: it rises 12 inches for every 12 inches of run.
How do I convert degrees to roof pitch?
Multiply the tangent of the angle by 12. For 35 degrees, 12 × tan(35°) = 8.4, so the pitch is about 8.4/12.
Last reviewed 2026-10-10. Results are estimates for planning; confirm quantities with your supplier and requirements with your local building code and the manufacturer's instructions.