Roof Pitch Angle and Slope Factor Charts
Roof Pitch is a term describing how steep or flat your roof slope is. The combination of two numbers are used to display or show the roof pitch. Two most common methods (4/12 or 4:12) are used for marking the pitch of a roof. On blue prints architects & engineers usually display the pitch of a roof in the format shown on the image where number (4) represents a rise and number (12) represents a length. This means if a roof rises 4' in the length of 12', your Roof Pitch would be 4/12 or 18.43 degrees.
Roof Pitch and Corresponding Angles
| Roof Pitch (slope) | Roof Angle (degree) |
|---|---|
| 1:12 Pitch | 4.76° |
| 2:12 Pitch | 9.46° |
| 3:12 Pitch | 14.04° |
| 4:12 Pitch | 18.43° |
| 5:12 Pitch | 22.62° |
| 6:12 Pitch | 26.57° |
| 7:12 Pitch | 30.26° |
| 8:12 Pitch | 33.69° |
| 9:12 Pitch | 36.87° |
| 10:12 Pitch | 39.81° |
| 11:12 Pitch | 42.51° |
| 12:12 Pitch | 45.00° |
| 13:12 Pitch | 47.29° |
| 14:12 Pitch | 49.40° |
| 15:12 Pitch | 51.34° |
| 16:12 Pitch | 53.13° |
ROOF PITCH CALCULATOR
| Pitch | Angle |
Slope Factor Chart 1:12 pitch - 6:12 pitch
| Pitch of Roof | 1:12 | 2:12 | 3:12 | 4:12 | 5:12 | 6:12 |
| Slope Factor | 1.0035 | 1.0138 | 1.0308 | 1.0541 | 1.0833 | 1.1180 |
| Valley & Hip Factor | 1.4167 | 1.4240 | 1.4362 | 1.4530 | 1.4743 | 1.5000 |
Slope Factor Chart 7:12 pitch - 12:12 pitch
| Pitch of Roof | 7:12 | 8:12 | 9:12 | 10:12 | 11:12 | 12:12 |
| Slope Factor | 1.1577 | 1.2019 | 1.2500 | 1.3017 | 1.3566 | 1.4142 |
| Valley & Hip Factor | 1.5298 | 1.5635 | 1.6008 | 1.6415 | 1.6853 | 1.7320 |
(A) x (Hip or Valley Factor) = (B)
A) x (Slope Factor) = (B)
