Roof Square Footage Calculator

How the Roof Square Footage Calculator works

Formula. Roof area = length × width × pitch factor. Base area = length × width.

Example. A 40 foot by 30 foot footprint with a pitch factor of 1.2 is 40 × 30 = 1,200 square feet of base area, and 1,200 × 1.2 = 1,440 square feet of roof.

Limitation. The pitch factor is typed in by the user. The page does not derive it from rise and run, and it does not add waste, hips, or valleys.