How Many Shingles for a 2,800 Square Foot House?
Roofing squares needed
34.4 squares
A 2,800 square foot footprint, 70 by 40, at a 6/12 pitch with ten percent waste.
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How that number is worked out
These are the figures this page was built with and every line the calculator produces from them. Change anything above and all of it moves.
- Building length70 ft
- Building width40 ft
- Roof pitch, rise per 12 in6 /12
- Waste allowance10 %
- Ridge length, 0 if unknown70 ft
Roofing squares needed34.4 squares
| Footprint area | 2,800 sq ft |
|---|---|
| Slope multiplier at 6/12 | 1.12 x |
| Actual roof surface | 3,130 sq ft |
| Squares before waste | 31.3 |
| Squares with 10% waste | 34.4order to this number |
The material list this produces
| Shingles, bundles (3 per square) | 104 |
|---|---|
| Synthetic underlayment, rolls (10 sq each) | 4 |
| Starter strip, linear ft | 252 |
| Ridge cap, linear ft | 70 |
| Drip edge, linear ft | 220 |
| Roofing nails, lb | 76 |
Roof pitch compared
Pitch is the number most people guess at, and it is worth more shingles than any other input. Same house, five pitches.
| Roof pitch | Roofing squares needed |
|---|---|
| 4/12 | 32.5 squares |
| 6/12 | 34.4 squares |
| 8/12 | 37 squares |
| 10/12 | 40.1 squares |
| 12/12 | 43.6 squares |
What else matters here
Twenty eight hundred square feet of footprint at 6/12 is 3,130 square feet of roof, 34.4 squares with waste, a hundred and four bundles.
Shingles carry a wind rating from the ASTM D3161 or D7158 test, and the classes are worth reading rather than skimming. D3161 runs class A, D and F at 60, 90 and 110 miles per hour. D7158 runs class D, G and H at roughly 90, 120 and 150. Most current architectural shingles are class F or class H, and the box will say so.
The rating is conditional and the conditions are where roofs actually fail. It assumes the six nail pattern, a proper starter course at the eaves and usually the rakes, the sealant strips fully bonded, and in cold weather hand sealing each tab with roofing cement because the strips need warm sun to activate. A 130 mile per hour shingle installed with four nails and no starter is not a 130 mile per hour roof, and the manufacturer will say exactly that after the storm.
What this calculator assumes
- Footprint times the slope multiplier gives the actual roof surface. A 6/12 roof is 11.8 percent larger than the ground it covers, which is the number most people forget.
- Three bundles per square is standard for both three tab and architectural shingles. Check your brand, a few premium lines run four.
- Synthetic underlayment is figured at 10 squares per roll, starter and ridge cap at one linear foot per foot.
Questions people ask
How many bundles of shingles for a 2,800 sq ft house?
About 104 bundles at a 6/12 pitch with ten percent waste, which is 34.4 squares.
What wind rating do shingles have?
Class A, D or F at 60, 90 or 110 mph under ASTM D3161, or class D, G or H at about 90, 120 or 150 under D7158. It is printed on the bundle.
What voids a shingle wind rating?
Missing the six nail pattern, no starter course, nails off the nail line, and unsealed tabs. In cold weather the tabs have to be hand sealed, because the adhesive needs sun to bond.
The roofing calculator takes any dimensions you like and hands back the same list.