Footprint40 x 30 ft, 12 in overhang
Pitch6/12 (factor 1.118)
Roof area1,503 sq ft
Bundles50 with 10% extra
A simple gable roof is the easiest to estimate: two rectangles, tilted.
Materials
| Item | Amount |
|---|---|
| Shingles | 50 bundles (16.5 squares) |
| Drip edge | eaves 84 ft plus rakes about 72 ft |
| Starter strip | 84 ft |
| Ridge cap | 42 ft |
| Underlayment | per roll coverage on the label |
Most asphalt shingles pack 3 bundles per square, as on GAF’s Timberline wrappers.
Before you start
Roofing is dangerous work. Many homeowners hire this out; if you do it yourself, use fall protection and check whether your town requires a permit.
Sources
Sources last checked 1 November 2026.
Calculators for this project
Frequently asked questions
How many bundles for a 40 x 30 house?
With a 6/12 pitch and 12 in overhangs, about 50 bundles including 10% waste.