Roofing Calculator
Estimate roofing material needed from the roof footprint, pitch, and a waste allowance.
Inputs explained
- Roof Length (ft) — The horizontal length of the roof in feet.
- Roof Width (ft) — The horizontal width of the roof in feet.
- Roof Pitch (rise/12) — The slope as rise per 12 inches of run. A 6 means 6/12 pitch.
- Waste Factor (%) — Extra material for cuts and overlap. 10–15% is typical.
How to use it
- Fill in the fields above — each input has a hint describing exactly what to enter
- Press Calculate to get your result instantly, right on this page
- Copy the result, save the tool to favorites, or share and embed it anywhere
Understanding the result
Example: A 40 ft × 30 ft roof at 6/12 pitch with 10% waste needs about 1,475 sq ft of material.
Frequently asked questions
Is the Roofing Calculator free to use? Yes — it is completely free, with no sign-up, no download and no usage limits. You can use it as often as you need.
Is my data private? Yes. The calculation runs entirely in your browser — the values you enter are never sent to our servers, stored or shared with anyone.
What information do I need? Just the following: Roof Length (ft), Roof Width (ft), Roof Pitch (rise/12), Waste Factor (%). Each field includes a hint explaining exactly what to enter.
Can I use it on my phone? Yes — the tool is fully responsive and works on any device, and the same calculator is available in the EasyWorkCalcs mobile app.
Privacy
Everything you enter into the Roofing Calculator is processed entirely in your browser. Nothing is uploaded, stored or shared — your data stays on your device.