Common rafter calculator
Calculate one sloping rafter from horizontal run, roof pitch and horizontal overhang.
Results
- Total rise
- 1.732051 m
- Length
- 4.041452 m
- Rafter tail length
- 0.57735 m
- Plumb face to rafter edge (°)
- 60
Method · Limits
Run and overhang are horizontal. Rise = run × tan(pitch); total length = (run + overhang) / cos(pitch). Plumb angle is measured between the vertical cut face and the rafter edge: 90° − pitch, not a saw setting. Ridge thickness, birdsmouth, cut allowances and structural capacity are excluded.
Inputs stay on this device. Files include your values; share them intentionally. This is geometry and purchasing arithmetic, not a structural or building-code assessment. Prices exclude tax and delivery.