Roof Pitch Calculator
Use this free roof pitch calculator to calculate roof pitch ratio, roof angle, and slope percentage from rise and run measurements.
What Is Roof Pitch?
Roof pitch is the measurement of how much a roof rises vertically for every 12 inches of horizontal run. For example, a roof that rises 6 inches for every 12 inches of run has a 6/12 pitch.
Roof Pitch Formula
Pitch = Rise ÷ Run
Roof Angle = arctangent(Rise ÷ Run)
Slope Percentage = (Rise ÷ Run) × 100
Example
If the rise is 6 inches and the run is 12 inches:
6 ÷ 12 = 6/12 roof pitch
The roof angle is approximately 26.57° and the slope is 50%.
Common Roof Pitch Chart
| Pitch | Angle | Slope |
|---|---|---|
| 4/12 | 18.43° | 33.33% |
| 5/12 | 22.62° | 41.67% |
| 6/12 | 26.57° | 50% |
| 8/12 | 33.69° | 66.67% |
| 12/12 | 45° | 100% |
FAQ
What does a 6/12 roof pitch mean?
A 6/12 roof pitch means the roof rises 6 inches for every 12 inches of horizontal run.
What is the angle of a 6/12 roof pitch?
A 6/12 roof pitch has an angle of approximately 26.57 degrees.
Is roof pitch important for roofing estimates?
Yes. Roof pitch can affect roof area, material needs, labor difficulty, and total roofing cost.