Roof Pitch Calculator
A free, browser-based calculator. Runs entirely in your browser — no sign up, nothing stored.
100% FreeRuns in your browserBasic
Enter Values
Enter your values and press Calculate to see results.
How to use this calculator
- Enter the roof's rise and run.
- Press Calculate for the angle and the pitch ratio.
How it works
Roof pitch is the steepness of a roof. From the rise and run, the angle is arctan(rise ÷ run), and the ratio is expressed as rise per 12 of run (for example 6:12).
Worked example
Rise 1, run 1. Angle = 45°, ratio 12:12.
Frequently asked questions
What's a common roof pitch?
Many homes sit between 4:12 and 9:12.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.