Construction
Shingle Calculator
Enter your roof footprint, pitch, and hip/ridge length to estimate the shingle bundles, synthetic underlayment rolls, ridge-cap bundles, and nails to order for a re-roof.
Quick answer: Asphalt shingles come 3 bundles to a roofing square (100 sq ft), so a 20-square roof needs about 60 bundles plus 10–15% for waste, 2 rolls of synthetic underlayment, ridge-cap shingles, and roughly 320 nails per square.
Frequently asked questions
How many bundles of shingles do I need?
Most asphalt shingles come 3 bundles to a roofing square (100 sq ft). Multiply your roof's squares by 3, then add 10–15% for waste, hips, and valleys.
How many shingles in a square?
One square covers 100 sq ft and takes 3 bundles of standard architectural or 3-tab shingles. Heavier designer shingles can run 4–5 bundles per square.
What else do I need besides shingles?
Plan on synthetic underlayment (about one 10-square roll per 1,000 sq ft), starter strip for the eaves, ridge-cap shingles for hips and ridges, drip edge, and roofing nails — about 320 per square.