Enter the roof rise and run to find the pitch ratio, angle in degrees, percent grade and the slope multiplier used to convert footprint area to roof area.
Roof pitch describes steepness as rise over run—the inches of vertical rise per 12 inches of horizontal run. A 6/12 pitch rises 6 inches for every 12 inches across. Enter your rise and run above to see the pitch expressed several ways.
The angle is the arctangent of rise divided by run. The percent grade is rise divided by run times 100. The slope multiplier—the diagonal length divided by the run—is what you multiply a roof's flat footprint by to get its true sloped area. A 6/12 roof has a multiplier of about 1.118, meaning the surface is roughly 12% larger than the footprint.
Use the roof pitch calculator to convert rise and run into pitch, angle, grade and slope multiplier. It helps translate horizontal roof footprint into sloped roof surface area.
Start with the calculator that matches how your material is sold: area, length, volume, count, weight or electrical load. Enter one work area at a time, use the unit selector beside each measurement, then review the order quantity and cost fields before comparing supplier quotes.
Most calculators can save the current estimate in your browser, reload named estimates, print a copy, switch to dark mode or create a shareable link. Those tools are intended for planning and communication; always confirm final quantities, coverage rates, density, code requirements and pricing with the supplier or contractor responsible for the work.