Roofing Calculator
Multiply horizontal roof area by the pitch factor √(1 + (rise/run)²).
This calculator is free to use. Enable JavaScript to enter your values and see a result instantly.
How it works
Multiply horizontal roof area by the pitch factor √(1 + (rise/run)²).
Worked example
A 6-in-12 pitch increases area by about 11.8% over the footprint.
Keep in mind
Eaves, dormers, and waste need separate allowance.