Free roofing calculators that show their work
Roof pitch, area, squares, shingles, metal panels and cost. Every tool shows the formula, a worked example and the assumptions, so you can check the numbers before you order or sign.
Quick roof pitch check
Most-used calculators
Shingle calculatorBundles, starter, ridge cap, underlayment, drip edge and nails in one go
Roof pitch calculatorRise and run to x/12, degrees and multipliers
Roof area calculatorFootprint plus pitch to true square footage
Metal roofing calculatorPanel count, cut length and screws
Roof replacement costPlanning ranges by material, with sources
Roofing squaresWhat a square is and how many you need
Built for three kinds of roof people
Homeowners
Find out how big your roof really is, what the pitch means, and what a fair price range looks like before contractors come out.
DIYers
Measure from the ground, get exact bundle and nail counts, and cut rafters right the first time.
Roofers and estimators
Fast takeoff math for the truck or the office: waste, underlayment, edge metal, cap and starter, nails and panel cut lists.
Every common roof pitch
Angle, multiplier, rafter lengths and area tables for each pitch: 1/12 · 2/12 · 3/12 · 4/12 · 5/12 · 6/12 · 7/12 · 8/12 · 9/12 · 10/12 · 11/12 · 12/12. Or see the full pitch-to-degrees chart.
Why RoofGenius
- Shows the math. Formulas, worked examples and tables on every page, so results can be checked by hand.
- No signup. Calculators run in your browser. Nothing you type is sent anywhere.
- Roofing calculators since 2001. RoofGenius has published roof pitch and estimating tools for over two decades, and the site was rebuilt from scratch in 2026.