Roofing & Exterior Calculators

ABOUT THESE TOOLS

Almost every roofing quantity starts from one number: true roof area, which is the footprint stretched by the pitch factor. These calculators run that chain — true area and squares from footprint and pitch, shingle bundles at the standard three bundles per square plus starter and ridge, the pitch multiplier itself (pitch to angle, slope factor, and rafter length in one conversion), underlayment rolls from area and overlap, metal panel counts and lineal feet from roof size and panel coverage width, and gutter footage with downspout counts from the roof’s drainage area.

Code requirements for roofing come from the IRC and IBC — underlayment type and lap, ice barrier where it applies, and fastening schedules by wind zone — with NRCA details and the manufacturer’s installation instructions governing the workmanship side; on most shingle warranties the manufacturer’s instructions are effectively code. These tools produce the order quantities; the spec and the local amendments decide the assembly. Free, in the browser, no account — fast enough to run from the ridge or the driveway estimate.