Roofing Calculator
Roofers price and order by the "square" — 100 square feet of roof. Enter your roof area to get the number of squares and how many shingle bundles to buy, with waste for cuts, ridges and valleys built in.
Your numbers
Result
- Roofing squares100 sq ft each
- 20
- Roof areasq ft
- 2,000
| Item | Value |
|---|---|
| Roof area | 2000 sq ft |
| Squares (100 sq ft each) | 20.00 |
| Bundles with 10% waste | 66 |
Squares and bundles
A roofing square is 100 sq ft. Divide the roof area by 100 for the squares, then multiply by the bundles per square — most asphalt shingles are 3 bundles per square. A 2,000 sq ft roof is 20 squares, or about 66 bundles with 10% waste. Heavier architectural shingles can be 4 or more bundles per square.
Use the actual roof area, not the footprint
A sloped roof has more area than the ground it covers. Multiply the footprint by a pitch (slope) factor — the roof pitch calculator gives it — before you size the shingles. A steep roof can be 20–40% larger than its footprint, so skipping this leaves you short.
Ridge, hip, starter and underlayment
Field shingles are only part of the order. Add ridge and hip cap shingles (sold by the linear foot), starter strip along the eaves, underlayment (felt or synthetic), drip edge and nails. Buy a little extra and keep a spare bundle for future repairs so the color matches.
Frequently asked questions
Sources
- Roofing coverage (square = 100 sq ft; bundles per square)
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