Free tool
Roofing calculator
Roof squares, shingle bundles, underlayment, and accessories from footprint and pitch.
Inputs
Estimated materials
- Shingle bundles (3 per square)
- 62 bundles
- Roofing squares (with waste)
- 20.5
- Roof surface area
- 1,860 SF (slope factor 1.118)
- Synthetic underlayment (10 sq rolls)
- 3 rolls
- Drip edge (10 ft pieces)
- 18 pieces
- Starter strip
- 176 LF
- Ridge cap
- 50 LF (~2 bundles)
- Coil nails (~320 per square)
- 6,549
Assumes a simple gable roof. Hip, valley, and cut-up roofs need 12–20% waste. Bundles per square and ridge-cap coverage vary by product — check the wrapper. Estimate — verify before ordering.
Frequently asked
- How many bundles of shingles do I need?
- Most architectural shingles come 3 bundles per square (100 SF). Find the sloped roof area, add 10–15% waste, divide by 100, and multiply by 3.
- How do I get roof area from the house footprint?
- Add the overhang to each side, multiply length by width, then multiply by the pitch's slope factor — about 1.118 for a 6/12 roof and 1.414 for 12/12.
- How much waste for shingles?
- About 10% for a simple gable, 12–15% for hips, and up to 20% for roofs with many valleys, dormers, and penetrations.
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