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RoofingRoofing Shingles Calculator — How Many Bundles Do I Need?
Enter the roof area — the actual length and width of the sloped surfaces, not the ground footprint — to estimate bundles of asphalt shingles, with 10% added for waste and starter/cap.
How this calculator works
Roofers measure in "squares" — 1 square = 100 sq ft = 3 bundles of standard architectural shingles. We take your roof area, add 10% for waste, starter strip, and ridge cap, and divide by 33.3 sq ft per bundle.
What changes how much you need
- Measure the actual sloped surface, not the building footprint — a steep roof has far more area than the floor below it.
- 1 square = 100 sq ft = 3 bundles (architectural). Some heavier shingles run 4 bundles per square.
- Buy extra starter strip and hip/ridge cap — they’re sold separately from field bundles.
- Add 10–15% waste for valleys, hips, and complex roofs.
Frequently asked questions
How many bundles of shingles per square?
Three bundles per square (100 sq ft) for standard architectural shingles. Heavier designer shingles can be four.
How do I find my roof area?
Measure each roof plane’s length × width and add them up. From the ground, multiply your footprint by a pitch factor (about 1.05–1.25 for common slopes).
How much waste should I add?
10% for a simple gable roof, up to 15% for roofs with lots of valleys and hips.