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Roofing Calculator

Calculate squares of shingles and materials needed based on roof footprint and pitch

Measurement Method

Roof Pitch

Pitch factor: 1.054× — a 4:12 pitch adds 5% more surface area than the footprint.

Shingle Type & Waste

%
10% simple roof · 15–20% for hips/valleys
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Enter your roof dimensions to calculate materials

Tips & Notes

  • 1 roofing square = 100 sq ft. Most shingles are sold 3 bundles per square.
  • Add 10% waste for a simple gable roof; 15–20% for hips, valleys, or dormers.
  • Architectural (dimensional) shingles last 25–30 years vs. 15–20 for 3-tab.
  • Check local building codes — most require ice and water shield at eaves in cold climates.
  • Never roof over more than 2 layers of shingles — strip to deck for best results.