About RoofGenius

RoofGenius.com has published roofing calculators since 2001. The original site offered roof pitch tools, measuring guides and RoofCalcWriter, a desktop estimating program for roofing contractors that has since been discontinued.

In 2026 we rebuilt the site from scratch around one idea: roofing calculators should show their work. Every tool on RoofGenius explains the formula it uses, walks through a worked example and lists its assumptions, so a homeowner, a DIYer or a roofer can check the number before relying on it.

How we build the calculators

• The math is standard geometry and trade practice: pitch multipliers, hip and valley factors, coverage per bundle and roll.
• Defaults come from typical product data and code minimums (mostly the International Residential Code). Where products vary, the calculator lets you enter the number from the wrapper.
• Calculations are covered by automated tests that check them against hand-worked answers.
• Cost figures come from published sources, named on the page, with the date we checked them.

What RoofGenius is not

We are not a contractor, an insurer or a lead-selling service, and nothing here is professional advice. For structural, code or insurance questions, talk to a licensed local professional.

RoofGenius.com is not affiliated with RoofGenius.ai or any other company with a similar name.

Found an error or want a calculator we do not have? Contact us.