Roof Pitch to Degrees
Convert between pitch (rise per 12), the angle in degrees and the percent slope. The calculator below is set to degrees: type the angle you have.
Roof pitch
6.93/12 pitch
30.0° · 57.7% · ×1.155
6.93/12 is 30.00°, a 57.7% slope, and the roof is 15.5% larger than its footprint.
- Angle30.00°
- Percent slope57.7%
- Pitch multiplier1.1547
- Hip and valley factor1.5275
- Rafter per foot of run13.86 in
- Slope class (OSHA)Steep (over 4 in 12)
Pitch is rise in inches over 12 inches of run. The multiplier turns a flat measurement into sloped length: multiply the footprint area by it to get roof area.
Planning estimate, not a quote. Disclaimer
Formulas
Rise per 12 = 12 × tan(degrees)
Percent = tan(degrees) × 100
A 6/12 roof is arctan(0.5) = 26.57°. A 30° roof is 12 × tan(30°) = 6.93, so about 7/12.
Degrees to roof pitch
| Angle | Pitch | Percent | Multiplier |
|---|---|---|---|
| 5° | 1.05/12 | 8.7% | 1.004 |
| 10° | 2.12/12 | 17.6% | 1.015 |
| 15° | 3.22/12 | 26.8% | 1.035 |
| 20° | 4.37/12 | 36.4% | 1.064 |
| 22.5° | 4.97/12 | 41.4% | 1.082 |
| 25° | 5.60/12 | 46.6% | 1.103 |
| 30° | 6.93/12 | 57.7% | 1.155 |
| 35° | 8.40/12 | 70.0% | 1.221 |
| 40° | 10.07/12 | 83.9% | 1.305 |
| 45° | 12.00/12 | 100.0% | 1.414 |
Roof pitch to degrees
| Pitch | Angle | Percent |
|---|---|---|
| 1/12 | 4.76° | 8.3% |
| 2/12 | 9.46° | 16.7% |
| 3/12 | 14.04° | 25.0% |
| 4/12 | 18.43° | 33.3% |
| 5/12 | 22.62° | 41.7% |
| 6/12 | 26.57° | 50.0% |
| 7/12 | 30.26° | 58.3% |
| 8/12 | 33.69° | 66.7% |
| 9/12 | 36.87° | 75.0% |
| 10/12 | 39.81° | 83.3% |
| 11/12 | 42.51° | 91.7% |
| 12/12 | 45.00° | 100.0% |
Two angles people search for: 30° is 6.93/12 (very close to 7/12, which is 30.3°) and 45° is exactly 12/12. For the full list see the roof pitch chart.
Frequently asked questions
How do you convert roof pitch to degrees?
Divide the rise by 12 and take the arctangent. For 4/12, arctan(4 ÷ 12) = 18.43°.
How do you convert degrees to roof pitch?
Multiply the tangent of the angle by 12. For 30°, 12 × tan(30°) = 6.93/12.
What pitch is a 45 degree roof?
A 12/12 pitch, which is a 100% slope.
What is a 30 degree roof pitch?
About 6.9/12. A 7/12 roof is 30.3°, so 7/12 is the nearest whole pitch.
How many degrees is a 6/12 pitch?
26.57 degrees.
Related
Other roofing calculators
Sources
- Swanson Tool: Roof pitch reference (rafter length per foot of run) (checked Nov 12, 2026)