Roof Pitch Calculator

Convert roof pitch to degrees and slope factor.

Rise (vertical, in)

Run (horizontal, in)

ROOF PITCH

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rise over run

Usage Tip

4:12 is a common residential pitch. Anything under 2:12 requires special low-slope roofing.

THE MATH

Angle = arctan(Rise ÷ Run)

Where: slope factor = √(Rise² + Run²) ÷ Run

• Pitch is expressed as rise per 12 in of run
• Slope factor scales flat area to sloped area

The calculators and tools on Formula Factory are provided for general guidance and informational purposes only. Results are estimates based on standard formulas and the values you enter — they do not constitute professional engineering, electrical, or architectural advice. Always verify calculations with a qualified professional before making decisions for any safety-critical, code-compliance, or commercial application. Formula Factory makes no representations or warranties as to the accuracy or completeness of any result, and accepts no liability for errors, omissions, or any outcomes arising from reliance on this information.