Free roofing tool

Roof Square Footage Calculator

Calculate roof square footage from measured area or a simple footprint and roof pitch, then convert the result to roofing squares.

Project measurements

Enter measured roof area directly, or estimate sloped area from a rectangular footprint and pitch.

Roofing squares
This is a geometry estimate. Complex hips, valleys, dormers and overhangs can require plane-by-plane measurement.

How this calculator works

If you know the measured roof surface area, the calculator uses that value directly. For a simple rectangular footprint, it can estimate sloped area by multiplying footprint area by the slope factor derived from the rise/run triangle.

For irregular roofs, plane-by-plane measurement is more reliable.