Shingles for a 30 × 40 ft house, by roof pitch
This is a typical ranch house of about 1,200 ft². With 12 in overhangs the roof footprint is 1344 ft² (32 × 42 ft). A sloped roof is larger than its footprint, so the steeper it is the more shingles it needs. Bundles include 10% waste at three per square:
| Pitch | Roof area | Squares | Bundles (10% waste) |
|---|---|---|---|
| 4/12 | 1,417 ft² | 14.2 | 47 |
| 6/12 | 1,503 ft² | 15.0 | 50 |
| 8/12 | 1,615 ft² | 16.2 | 54 |
| 10/12 | 1,749 ft² | 17.5 | 58 |
| 12/12 | 1,901 ft² | 19.0 | 63 |
How waste changes the order (6/12 pitch)
| Waste | Squares to order | Bundles |
|---|---|---|
| 10% | 16.5 | 50 |
| 15% | 17.3 | 52 |
| 20% | 18.0 | 55 |
What is not in these numbers
These figures assume a simple gable or hip roof over the whole footprint. Dormers, valleys, chimneys, porches and garages add area. Starter strips, ridge caps, drip edge, flashing and nails are also bought separately. See the roofing squares guide for the full list.
Want to change anything else? The calculator above is the full Roofing Calculator: edit any number and the results update instantly.
Tools & materials for this project
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Frequently asked questions
How many bundles of shingles for a 30x40 house?
For a simple roof at 6/12 pitch with 12 in overhangs and 10% waste, about 50 bundles (16.5 squares at three bundles per square). Steeper roofs need more, as the table shows.
How many squares of roofing is a 30x40 house?
The roof is about 15.0 squares at 6/12 pitch (1,503 ft²), or 16.5 squares with 10% waste. One square is 100 ft² of roof.
How many rolls of underlayment for a 30x40 roof?
About 2 rolls of 1,000 ft² synthetic underlayment at 6/12 pitch, including 10% for laps.
Related sizes and guides
Estimates only. Results assume standard materials and simple shapes. Supplier products vary, and the final call on quantity, structure and safety is yours. Check your local code and your supplier's guidance before ordering.