Roofing Squares & Shingle Bundles Calculator
Enter your roof dimensions and pitch below. Results include roofing squares, shingle bundles, and a recommended waste factor — ready to use on your bid or material order.
How roofing squares are calculated
One roofing square = 100 sq ft of roof surface. Multiply your roof's footprint (length × width) by the pitch multiplier to get the actual sloped surface area, then divide by 100. A 4/12 pitch adds about 5% more area than a flat measurement.
How many shingles per square?
Standard 3-tab and architectural shingles both cover 1 square per 3 bundles. Each bundle covers roughly 33.3 sq ft. Always add a waste factor — 15% for a simple gable, 20–25% for hip roofs or roofs with multiple valleys and dormers.
Pitch multipliers at a glance
4/12 pitch = 1.054 multiplier. 6/12 = 1.118. 8/12 = 1.202. 12/12 = 1.414. The steeper the roof, the more material you need. Our calculator applies the correct multiplier automatically based on your selected pitch.
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