Roof Pitch Chart
A roof pitch chart converts the rise-per-12 ratio into an angle, a slope percentage and the multipliers used for area and hip/valley framing. A 4:12 pitch is 18.43° and a 33.3% slope; 6:12 is 26.57° and 50%; 12:12 is exactly 45° and 100%.
Need a value that is not on the chart? Use the roof pitch calculator — it solves from rise and run, an angle, a percentage, or a rafter length.
Pitch to degrees conversion table
| Pitch | Degrees | Slope % | Pitch multiplier | Hip / valley factor |
|---|---|---|---|---|
| 0.25:12 | 1.19° | 2.1% | 1.0002 | 1.4144 |
| 0.5:12 | 2.39° | 4.2% | 1.0009 | 1.4148 |
| 1:12 | 4.76° | 8.3% | 1.0035 | 1.4167 |
| 1.5:12 | 7.13° | 12.5% | 1.0078 | 1.4197 |
| 2:12 | 9.46° | 16.7% | 1.0138 | 1.424 |
| 2.5:12 | 11.77° | 20.8% | 1.0215 | 1.4295 |
| 3:12 | 14.04° | 25% | 1.0308 | 1.4361 |
| 3.5:12 | 16.26° | 29.2% | 1.0417 | 1.444 |
| 4:12 | 18.43° | 33.3% | 1.0541 | 1.453 |
| 4.5:12 | 20.56° | 37.5% | 1.068 | 1.4631 |
| 5:12 | 22.62° | 41.7% | 1.0833 | 1.4743 |
| 5.5:12 | 24.62° | 45.8% | 1.1 | 1.4866 |
| 6:12 | 26.57° | 50% | 1.118 | 1.5 |
| 6.5:12 | 28.44° | 54.2% | 1.1373 | 1.5144 |
| 7:12 | 30.26° | 58.3% | 1.1577 | 1.5298 |
| 7.5:12 | 32.01° | 62.5% | 1.1792 | 1.5462 |
| 8:12 | 33.69° | 66.7% | 1.2019 | 1.5635 |
| 8.5:12 | 35.31° | 70.8% | 1.2255 | 1.5817 |
| 9:12 | 36.87° | 75% | 1.25 | 1.6008 |
| 9.5:12 | 38.37° | 79.2% | 1.2754 | 1.6207 |
| 10:12 | 39.81° | 83.3% | 1.3017 | 1.6415 |
| 10.5:12 | 41.19° | 87.5% | 1.3288 | 1.663 |
| 11:12 | 42.51° | 91.7% | 1.3566 | 1.6853 |
| 11.5:12 | 43.78° | 95.8% | 1.3851 | 1.7083 |
| 12:12 | 45° | 100% | 1.4142 | 1.7321 |
| 13:12 | 47.29° | 108.3% | 1.4743 | 1.7815 |
| 14:12 | 49.4° | 116.7% | 1.5366 | 1.8333 |
| 15:12 | 51.34° | 125% | 1.6008 | 1.8875 |
| 16:12 | 53.13° | 133.3% | 1.6667 | 1.9437 |
| 18:12 | 56.31° | 150% | 1.8028 | 2.0616 |
| 20:12 | 59.04° | 166.7% | 1.9437 | 2.1858 |
| 24:12 | 63.43° | 200% | 2.2361 | 2.4495 |
Minimum pitch by material
| Material | Minimum pitch | Code reference |
|---|---|---|
| Asphalt shingles (standard) | 4:12 | IRC R905.2.2 |
| Asphalt shingles (double underlayment) | 2:12 | IRC R905.2.2 exception |
| Standing seam metal | 0.25:12 | IRC R905.10.1.1, 1/4:12 |
| Corrugated / exposed-fastener metal | 3:12 | IRC R905.10.1.1 |
| Clay or concrete tile | 2.5:12 | IRC R905.3.1 |
| Slate | 4:12 | IRC R905.6.1 |
| Wood shingles | 3:12 | IRC R905.7.1 |
| Wood shakes | 4:12 | IRC R905.8.6 |
| EPDM / TPO / PVC membrane | 0.25:12 | IRC R905.11–R905.13 |
| Modified bitumen | 0.25:12 | IRC R905.11 |
Source: 2021 International Residential Code, Chapter 9. Manufacturer instructions may set a steeper minimum.