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Roof pitch calculator
Translate rise and horizontal run into an angle and rafter length.
A clear answer. Here’s how.
Use matching units for rise and horizontal run. Angle = atan(rise/run), rafter length = hypot(rise,run), and rise per 12 = 12 × rise/run. Eaves, ridge cuts, material thickness and structural design are excluded.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Vertical rise
- 3
- Horizontal run
- 6
Example result
- Pitch angle
- 26.5650511771°
- Rise per 12 run
- 6
- Sloping length
- 6.7082039325