Estimate roof shingles in bundles and squares. Enter your roof dimensions (both slopes combined), set the waste factor for valleys and hips, and get an optional cost estimate from your per-bundle price.
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How to use this calculator
- Measure the roof’s length and slope width, then double the width to cover both slopes (or measure each slope and add).
- Set waste — 10% for simple gable roofs, 15%+ for hips, valleys, and dormers.
- Add your supplier’s price per bundle for a cost estimate.
The math behind it
Squares = roof area ÷ 100 sq ft, plus waste. Bundles = squares × 3 (three bundles per square for standard shingles), rounded up. Ridge cap estimate assumes roughly one bundle per 3 squares.
FAQs
How many bundles of shingles do I need?
A 40×30 ft roof (both slopes, 1,200 sq ft) with 10% waste needs about 40 bundles — 13.2 squares. Architectural shingles sometimes need 4 bundles per square; check the wrapper.
What is a roofing square?
100 square feet of roof area. Roofers quote and order by the square — it’s the industry’s standard unit.