Roof Pitch Chart: Angles and Multipliers
A reference chart converting each whole roof pitch to an angle, a percent slope and the multipliers used for area and rafters.
This chart is generated from the same formulas the calculators use, so it is internally consistent with every result on the site. Use it as a quick lookup, then open the pitch calculator for an exact in-between value.
| Pitch | Angle | Percent | Area multiplier | Hip multiplier |
|---|---|---|---|---|
| 1/12 | 4.76° | 8.3% | 1.003 | 1.417 |
| 2/12 | 9.46° | 16.7% | 1.014 | 1.424 |
| 3/12 | 14.04° | 25% | 1.031 | 1.436 |
| 4/12 | 18.43° | 33.3% | 1.054 | 1.453 |
| 5/12 | 22.62° | 41.7% | 1.083 | 1.474 |
| 6/12 | 26.57° | 50% | 1.118 | 1.5 |
| 7/12 | 30.26° | 58.3% | 1.158 | 1.53 |
| 8/12 | 33.69° | 66.7% | 1.202 | 1.563 |
| 9/12 | 36.87° | 75% | 1.25 | 1.601 |
| 10/12 | 39.81° | 83.3% | 1.302 | 1.641 |
| 11/12 | 42.51° | 91.7% | 1.357 | 1.685 |
| 12/12 | 45° | 100% | 1.414 | 1.732 |
Conversion examples
A 4/12 pitch is about 18.43 degrees and a 33.3 percent slope. An 8/12 pitch is about 33.69 degrees and a 66.7 percent slope. The area multiplier grows slowly at low pitches and faster as the roof steepens, which is why a steep roof needs noticeably more material for the same footprint.
Percent vs. degree confusion
Percent slope and degrees are different units. Percent is 100 times the rise-over-run ratio; degrees come from its arctangent. They only coincide near zero. Reading a 50 percent slope as 50 degrees would nearly double the true steepness.
Which pitches are suitable for which roof coverings is set by manufacturer instructions and local requirements, not by geometry. This chart tells you the angle and the material multiplier; it does not tell you whether a given shingle is approved at that slope.