Roofing calculator
Roof Pitch Calculator
Calculate roof pitch angle and slope multiplier from rise over run.
Your measurements
Estimated result
Pitch6:12
Angle26.6°
Slope factor1.118
Slope50%
Planning estimate only. Check product specifications, site conditions and local codes before ordering or building.
Roof pitch formula
Angle = arctan(rise ÷ run). Slope factor = √(rise² + run²) ÷ run.
Planning notes
For the familiar x:12 roof-pitch format, use a 12-inch run. The slope factor can then be used to convert a simple horizontal roof-plan area into an approximate sloped surface area.
- A 6:12 pitch rises 6 inches for every 12 inches of horizontal run.
- Use the slope factor to estimate sloped roof area from plan area.
Keep calculating
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