How to Estimate Asphalt Shingles
Asphalt shingles are sold by the bundle, with most products delivering 3 bundles per square (100 sq ft). Estimating the right number of bundles starts with the actual sloped roof area, plus ridge cap, starter strips, and nails.
Bundles Needed Formula
Bundles=Squares×Bundles per Square
Shingle Type Comparison
| Type | Bundles / Sq | Lifespan | Cost / Sq |
|---|---|---|---|
| 3-Tab | 3 | 20-25 yr | $75 - $100 |
| Architectural | 3 | 30-50 yr | $110 - $160 |
| Premium / Designer | 4 | 50+ yr | $200 - $400 |
| Metal shingle | 3 | 40-60 yr | $300 - $600 |
Ridge Cap and Accessories
Ridge cap shingles are pre-bent to wrap the ridge and any hip lines. One bundle typically covers 25 to 35 linear feet. Starter strips run along all eaves to seal the edge before the first course of field shingles.
Waste by Roof Complexity
Add 10% waste for a simple gable roof, 12 to 15% for hip roofs with diagonal cuts, and 15 to 20% for complex roofs with multiple valleys, dormers, or skylights.Buy from One Lot
Always purchase your full order from the same production lot. Asphalt shingle color varies between batches due to granule variation, so mismatched lots can create visible color stripes on the finished roof.