DIY Calculator
Roof Pitch Calculator
Calculate roof pitch, angle, and slope factor from rise and run.
Calculator guide
How this calculator works
How to use this calculator
Enter the project measurements and material details requested in the calculator. Then click Calculate to estimate the result. For best accuracy, measure carefully and update any default material values based on your supplier or project plan.
Formula used
Pitch = Rise ÷ Run. Angle = arctan(Rise ÷ Run). Slope Factor = √(Rise² + Run²) ÷ Run.
Example calculation
For a 6 inch rise and 12 inch run, the pitch is 6:12, the angle is 26.57°, and the slope factor is 1.118.
What the result means
The result helps describe roof steepness and estimate roof surface adjustments compared with flat horizontal area.
Frequently asked questions
What is slope factor used for?
Slope factor helps convert flat roof footprint area into estimated sloped roof surface area.