Roof Pitch in Degrees: Chart and Converter
Switch between the x/12 pitch roofers use and the angle a saw, phone app or solar installer wants. 4/12, 4:12, "4 in 12" and "4 on 12" all mean the same pitch: 4 inches of rise per 12 inches of run.
Pitch to degrees
Degrees to pitch
Common roof pitches in degrees
| Pitch | Also written | Degrees | Slope % |
|---|---|---|---|
| 1/12 | 1:12, 1 in 12 | 4.76° | 8.3% |
| 2/12 | 2:12, 2 in 12 | 9.46° | 16.7% |
| 3/12 | 3:12, 3 in 12 | 14.04° | 25.0% |
| 4/12 | 4:12, 4 in 12 | 18.43° | 33.3% |
| 5/12 | 5:12, 5 in 12 | 22.62° | 41.7% |
| 6/12 | 6:12, 6 in 12 | 26.57° | 50.0% |
| 7/12 | 7:12, 7 in 12 | 30.26° | 58.3% |
| 8/12 | 8:12, 8 in 12 | 33.69° | 66.7% |
| 9/12 | 9:12, 9 in 12 | 36.87° | 75.0% |
| 10/12 | 10:12, 10 in 12 | 39.81° | 83.3% |
| 12/12 | 12:12, 12 in 12 | 45.00° | 100.0% |
What is 1:12 in degrees?
1:12 is 4.76 degrees (arctan(1 ÷ 12)), an 8.33% slope. On a roof, 1/12 is a low-slope pitch that needs a membrane or low-slope metal, not shingles. The same 1:12 ratio is the maximum slope the ADA allows for a wheelchair ramp, which is why "1:12 in degrees" comes up so often: 1 inch of rise for every 12 inches of length, 4.76°.
Half pitches in degrees (0.5/12 to 11.5/12)
| Pitch | Degrees | Pitch | Degrees |
|---|---|---|---|
| 0.5/12 | 2.39° | 6.5/12 | 28.44° |
| 1.5/12 | 7.13° | 7.5/12 | 32.01° |
| 2.5/12 | 11.77° | 8.5/12 | 35.31° |
| 3.5/12 | 16.26° | 9.5/12 | 38.37° |
| 4.5/12 | 20.56° | 10.5/12 | 41.19° |
| 5.5/12 | 24.62° | 11.5/12 | 43.78° |
Degrees to roof pitch chart
| Angle | Pitch (rise per 12) | Nearest whole pitch | Slope % |
|---|---|---|---|
| 5° | 1.05/12 | 1/12 | 8.7% |
| 10° | 2.12/12 | 2/12 | 17.6% |
| 14° | 2.99/12 | 3/12 | 24.9% |
| 15° | 3.22/12 | 3/12 | 26.8% |
| 18° | 3.90/12 | 4/12 | 32.5% |
| 20° | 4.37/12 | 4/12 | 36.4% |
| 22.5° | 4.97/12 | 5/12 | 41.4% |
| 25° | 5.60/12 | 6/12 | 46.6% |
| 27° | 6.11/12 | 6/12 | 51.0% |
| 30° | 6.93/12 | 7/12 | 57.7% |
| 33° | 7.79/12 | 8/12 | 64.9% |
| 35° | 8.40/12 | 8/12 | 70.0% |
| 40° | 10.07/12 | 10/12 | 83.9% |
| 45° | 12.00/12 | 12/12 | 100.0% |
| 50° | 14.30/12 | 14/12 | 119.2% |
| 60° | 20.78/12 | 21/12 | 173.2% |
A 25 degree roof is a 5.60/12 pitch, so about 5.5/12 to 5.6/12. A 30 degree roof is 6.93/12, close to 7/12.
Slope percent to degrees
Percent slope is rise ÷ run × 100, so a 12% slope rises 12 ft per 100 ft. Degrees = arctan(percent ÷ 100). 12% is 6.84° (a 1.44/12 pitch), 25% is 14.04° (3/12), 50% is 26.57° (6/12) and 100% is 45° (12/12).
The conversion
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 |
Every pitch in half steps: degrees, multiplier and what it allows
Half-inch steps up to 12/12, then whole inches to 24/12, with the OSHA roof class and the point where each roofing material becomes code-legal.
| Pitch | Degrees | Slope % | Area multiplier | Roof class | Code minimum reached (IRC R905) |
|---|---|---|---|---|---|
| 0.5/12 | 2.39° | 4.2% | 1.0009 | Low-slope (OSHA) | Now allowed: Standing-seam metal panels; Built-up, modified bitumen, single-ply membrane; Lapped metal panels with lap sealant |
| 1/12 | 4.76° | 8.3% | 1.0035 | Low-slope (OSHA) | Now allowed: Mineral-surfaced roll roofing |
| 1.5/12 | 7.13° | 12.5% | 1.0078 | Low-slope (OSHA) | |
| 2/12 | 9.46° | 16.7% | 1.0138 | Low-slope (OSHA) | Now allowed: Asphalt shingles |
| 2.5/12 | 11.77° | 20.8% | 1.0215 | Low-slope (OSHA) | Now allowed: Clay and concrete tile |
| 3/12 | 14.04° | 25.0% | 1.0308 | Low-slope (OSHA) | Now allowed: Metal roof shingles; Lapped metal panels, no sealant; Wood shingles and shakes |
| 3.5/12 | 16.26° | 29.2% | 1.0417 | Low-slope (OSHA) | |
| 4/12 | 18.43° | 33.3% | 1.0541 | Low-slope (OSHA) | Now allowed: Slate |
| 4.5/12 | 20.56° | 37.5% | 1.0680 | Steep roof (OSHA) | |
| 5/12 | 22.62° | 41.7% | 1.0833 | Steep roof (OSHA) | |
| 5.5/12 | 24.62° | 45.8% | 1.1000 | Steep roof (OSHA) | |
| 6/12 | 26.57° | 50.0% | 1.1180 | Steep roof (OSHA) | |
| 6.5/12 | 28.44° | 54.2% | 1.1373 | Steep roof (OSHA) | |
| 7/12 | 30.26° | 58.3% | 1.1577 | Steep roof (OSHA) | |
| 7.5/12 | 32.01° | 62.5% | 1.1792 | Steep roof (OSHA) | |
| 8/12 | 33.69° | 66.7% | 1.2019 | Steep roof (OSHA) | |
| 8.5/12 | 35.31° | 70.8% | 1.2255 | Steep roof (OSHA) | |
| 9/12 | 36.87° | 75.0% | 1.2500 | Steep roof (OSHA) | |
| 9.5/12 | 38.37° | 79.2% | 1.2754 | Steep roof (OSHA) | |
| 10/12 | 39.81° | 83.3% | 1.3017 | Steep roof (OSHA) | |
| 10.5/12 | 41.19° | 87.5% | 1.3288 | Steep roof (OSHA) | |
| 11/12 | 42.51° | 91.7% | 1.3566 | Steep roof (OSHA) | |
| 11.5/12 | 43.78° | 95.8% | 1.3851 | Steep roof (OSHA) | |
| 12/12 | 45.00° | 100.0% | 1.4142 | Steep roof (OSHA) | |
| 13/12 | 47.29° | 108.3% | 1.4743 | Steep roof (OSHA) | |
| 14/12 | 49.40° | 116.7% | 1.5366 | Steep roof (OSHA) | |
| 15/12 | 51.34° | 125.0% | 1.6008 | Steep roof (OSHA) | |
| 16/12 | 53.13° | 133.3% | 1.6667 | Steep roof (OSHA) | |
| 17/12 | 54.78° | 141.7% | 1.7341 | Steep roof (OSHA) | |
| 18/12 | 56.31° | 150.0% | 1.8028 | Steep roof (OSHA) | |
| 19/12 | 57.72° | 158.3% | 1.8727 | Steep roof (OSHA) | |
| 20/12 | 59.04° | 166.7% | 1.9437 | Steep roof (OSHA) | |
| 21/12 | 60.26° | 175.0% | 2.0156 | Steep roof (OSHA) | |
| 22/12 | 61.39° | 183.3% | 2.0883 | Steep roof (OSHA) | |
| 23/12 | 62.45° | 191.7% | 2.1619 | Steep roof (OSHA) | |
| 24/12 | 63.43° | 200.0% | 2.2361 | Steep roof (OSHA) |
Minimum roof pitch by material
| Roof covering | Minimum pitch | Degrees | IRC section | Note |
|---|---|---|---|---|
| Standing-seam metal panels | 0.25/12 | 1.19° | R905.10.2 | — |
| Built-up, modified bitumen, single-ply membrane (TPO, EPDM, PVC) | 0.25/12 | 1.19° | R905.9, R905.11, R905.12 | Design slope for drainage |
| Lapped metal panels with lap sealant | 0.5/12 | 2.39° | R905.10.2 | — |
| Mineral-surfaced roll roofing | 1/12 | 4.76° | R905.5.2 | — |
| Asphalt shingles | 2/12 | 9.46° | R905.2.2 | Double underlayment from 2/12 up to 4/12 |
| Clay and concrete tile | 2.5/12 | 11.77° | R905.3.2 | Double underlayment from 2.5/12 up to 4/12 |
| Metal roof shingles | 3/12 | 14.04° | R905.4.2 | — |
| Lapped metal panels, no sealant (exposed-fastener) | 3/12 | 14.04° | R905.10.2 | — |
| Wood shingles and shakes | 3/12 | 14.04° | R905.7, R905.8 | Shorter exposure below 4/12 |
| Slate | 4/12 | 18.43° | R905.6.2 | — |
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
Sources
- International Code Council, International Residential Code (2021 and 2024), Section R905 minimum slopes, as summarized in IRC 2024 Chapter 9 (UpCodes) and the MyBuildingPermit residential re-roof checklist. Local amendments and manufacturer instructions can be stricter.
- OSHA, 29 CFR 1926.500(b): a low-slope roof is 4 in 12 or less; a steep roof is greater than 4 in 12. 1926.501(b)(13) requires fall protection for residential construction work 6 ft or more above a lower level.
Frequently asked questions
What is 1:12 in degrees?
A 1:12 slope (1/12 pitch) is 4.76 degrees, or an 8.33% grade. It is also the steepest slope the ADA allows for a ramp.
How many degrees is a 2/12 pitch?
A 2/12 pitch is 9.46 degrees.
How many degrees is a 3/12 roof pitch?
A 3/12 pitch is 14.04 degrees.
How many degrees is a 4/12 roof pitch?
A 4/12 pitch is 18.43 degrees.
How many degrees is a 5/12 pitch?
A 5/12 pitch is 22.62 degrees.
How many degrees is a 6/12 pitch?
A 6/12 pitch is 26.57 degrees.
How many degrees is an 8/12 pitch?
An 8/12 pitch is 33.69 degrees.
What pitch is a 25 degree roof?
A 25-degree roof is about a 5.6/12 pitch (12 × tan 25° = 5.60).
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 2026-10-21. Results are estimates for planning; confirm quantities with your supplier and requirements with your local building code and the manufacturer's instructions.