Disclaimer

Draft: the owner's legal business name will be added here before launch.

Last updated November 12, 2026.

FreeRoofingCalculators.com provides free calculators for general information and planning. Results are estimates.

Not a quote or professional advice

Nothing on this site is a quote, an offer to sell, or engineering, architectural, construction, safety, legal or financial advice. Rafter lengths are geometry only: they do not size lumber, check spans or loads, or replace plans stamped by a professional.

What can differ from your roof

• Real roofs have valleys, dormers, chimneys, skylights and several pitches. The calculators use a simple model; allow extra material and have a roofer measure.
• Shingle, underlayment, nail and panel figures are manufacturers' published data for specific products. Your product may differ. Read the wrapper and data sheet.
• Building codes set underlayment, ice barrier, slope and fastening rules. Local code and the manufacturer's instructions win over this site.
• Cost estimates use only the prices you enter. We publish no price data and make no claim about what a roof costs.

Safety

Falls from roofs cause serious injury and death. Use proper fall protection, follow OSHA and local rules, and consider hiring a professional.

Use at your own risk

You are responsible for confirming quantities, measurements and compliance before you buy or build. See also the terms and methodology.