Roofing Calculator

How the roofing estimate works

The calculator starts with the roof plan area, applies a slope multiplier from the pitch you enter, then adds your waste allowance. It converts that adjusted area into roofing squares and bundles based on the coverage per bundle.

What is a roofing square?

One roofing square equals 100 square feet of roof surface. Shingles are usually packaged in bundles, and bundle coverage varies by product, so use the coverage printed on the package for your final order.

Before ordering shingles

Hips, valleys, dormers, ridge caps, starter shingles, flashing, underlayment, drip edge, vents, and unusual roof geometry can increase material needs. Measure each roof section carefully and verify manufacturer instructions before purchase.