Roof pitch, explained
By the Tapepal teamUpdated 4 min read
Quick answer
Pitch is rise over run: how many inches the roof climbs for every 12 inches across. A 6/12 roof is an angle of 26.6°.
On this page4 sections
Pitch, angle and slope
| Pitch | Angle | Slope |
|---|---|---|
| 3/12 | 14.0° | 25% |
| 4/12 | 18.4° | 33% |
| 6/12 | 26.6° | 50% |
| 8/12 | 33.7° | 67% |
| 9/12 | 36.9° | 75% |
| 12/12 | 45.0° | 100% |
Measure it from inside
- Find a rafterIn the attic, or on the end of a rafter you can reach safely.
- Hold a level flatMark 12 in along the level from where it touches the rafter.
- Measure straight upFrom the 12 in mark to the rafter. That is the rise: 6 in means 6/12.
Turn degrees into pitch
Multiply 12 by the tangent of the angle. 30° gives 12 × 0.577 = 6.9/12, close to 7/12.
Free toolRoof pitchRise over run, the angle and the slope, from any two numbers.Or measure the angle with your phone
With your iPhoneThe level reads the angle.Hold your iPhone against a rafter. Tapepal shows the angle in degrees.
Questions
What is a common roof pitch?
Most houses sit between 4/12 and 9/12.
Is pitch the same as slope?
Pitch is written as rise over 12. Slope is the same idea as a percentage: 6/12 is 50%.
What is a low-slope roof?
Anything under 3/12. It needs different roofing materials.
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