The Roof Pitch Calculator helps you find your roof’s pitch, angle, and rafter length using either a rise-and-run measurement or a known roof angle. Simply fill in the fields above and click Calculate to get an instant result.
This calculator is part of Calculate Wiki’s Construction Calculators collection.
What You’ll Need
- Rise (inches) or Roof Angle (degrees)
- Run (inches) — typically 12 for standard pitch notation
- Horizontal Span (feet) — optional, for rafter length and ridge height
Formula Used
Angle = arctan(rise ÷ run)
Rafter length = √(span² + (span × rise ÷ run)²)
Example Calculation
Using example inputs — Rise = 6 in; Run = 12 in — the Roof Pitch Calculator returns:
| Value | Result |
|---|---|
| Pitch | 6/12 |
| Angle | 26.57° |
| Slope | 50% |
6/12 pitch, 26.57° angle, 50% slope — a moderate slope common on standard residential roofs.
Helpful Information
Results from the Roof Pitch Calculator are estimates based on standard formulas used in the construction calculators field. For projects with significant cost, safety, or structural implications, consider verifying results with a qualified roofing contractor or structural engineer.