How Much Roofing Material Do I Need?

Multiply your footprint by the pitch multiplier to get roof area, then divide by 100 for squares. Shingles come three bundles per square.

Worked example

A 40 ft × 30 ft footprint at 6/12 pitch has a 1.118 multiplier: 1,200 × 1.118 = 1,342 sq ft ≈ 13.4 squares ≈ 41 bundles.

Estimate roofing squares and shingle bundles by footprint and pitch.

Calculate rafter length and count from span, pitch, and spacing.

Estimate siding squares for your home's exterior walls.