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The angle of a roof is a measure of the underside of the roof from the horizontal as shown in the diagram. If you can access the rafters in your property and can measure the angle it is this angle you are measuring.
The slope of the roof (Pitch) is the ratio of vertical distance (Rise) to Horizontal distance (Run). It can be calculated using a set run of 12” and finding the rise at that point on the roof (See diagram).
The slope ratio (Pitch) can be converted into an approximate angle using the following table for your convenience.
| Roof Pitch | Angle |
| 1/12 | 4.76° |
| 2/12 | 9.46° |
| 3/12 | 14.04° |
| 4/12 | 18.43° |
| 5/12 | 22.62° |
| 6/12 | 26.57° |
| Roof Pitch | Angle |
| 7/12 | 30.26° |
| 8/12 | 33.69° |
| 9/12 | 36.37° |
| 10/12 | 39.81° |
| 11/12 | 42.51° |
| 12/12 | 45.00° |
