Roofing Calculator
Estimate pitched roof area, roofing squares, bundles, and underlayment.
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How this calculator works
Roof area = (length + 2 × overhang) × (width + 2 × overhang) × √(1 + (pitch ÷ 12)²). For a uniform pitch, this works for the projected footprint of a simple gable, hip, or shed roof. One roofing square is 100 sq ft. Bundles and underlayment round up using the specified coverage.
Use current quotes, local rates, and measured dimensions to make this estimate useful for your situation.
Frequently asked questions
How many bundles of shingles do I need?+
Multiply waste-adjusted roofing squares by the manufacturer’s bundles per square and round up. Ridge caps and starter shingles may be separate.
Does a hip roof need a different allowance?+
The uniform-slope area formula is the same, but hip cuts and caps often need additional waste. Increase the editable waste allowance for your actual layout.