Roofing Calculator · Practical guide
How Many Shingles Do I Need for 1500 Square Feet?
A 1,500 sq ft footprint at a 6/12 pitch works out to roughly 17 squares — about 51 shingle bundles before waste.
At a glance
The Quick Answer
For a house with a 1,500-square-foot footprint and a typical 6/12 gable roof, the calculator above returns about 1,677 sq ft of roof area, 16.8 squares, and 51 bundles of standard three-tab or architectural shingles. Plan on roughly 56 bundles once you add the customary 10% waste allowance.
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Enter your own values, then compare the result with the examples below.
Roofing Estimate
Add 10-15% extra for waste and starter strips. Consult a roofer for precise estimates.
Where the Numbers Come From
The roof surface is bigger than the floor plan because of the slope. A 6/12 pitch rises 6 inches per 12 inches of run, giving a pitch factor of √(1 + (6/12)²) = 1.118. So 1,500 × 1.118 = 1,677 sq ft. Dividing by 100 gives 16.8 squares, and at three bundles per square that is 50.3 — which the calculator rounds up to 51 bundles.
How Pitch Changes the Count
| Pitch | Roof Area | Squares | Bundles |
|---|---|---|---|
| Flat (0/12) | 1,500 sq ft | 15.0 | 45 |
| 4/12 | 1,581 sq ft | 15.8 | 48 |
| 6/12 | 1,677 sq ft | 16.8 | 51 |
| 8/12 | 1,803 sq ft | 18.0 | 54 |
| 12/12 | 2,121 sq ft | 21.2 | 64 |
A steeper roof needs more material over the same footprint: going from 4/12 to 12/12 adds a third more shingles on this house.
Do Not Skip the Waste Allowance
Standard practice adds 10–15% extra for cutting waste at rakes and valleys, starter strips along the eaves, and a few spare bundles for future repairs. Ten percent over 51 bundles is 56; on a hip roof with many diagonal cuts, budget toward the 15% end, or about 59 bundles. Enter your exact length, width, and pitch above to check your own numbers before ordering.
Frequently Asked Questions
Is 1500 square feet the footprint or the roof area?
Usually the footprint — the heated floor area. The actual roof surface is larger because of the slope: at a 6/12 pitch it is about 12% bigger. Enter your building dimensions and pitch in the calculator to get the true roof area.
How many bundles is that per square?
Three bundles cover one roofing square (100 sq ft) for standard asphalt shingles. So 16.8 squares needs about 51 bundles before waste.
Does a hip roof change the shingle count?
The sloped area comes out nearly the same for the same footprint and pitch, but hip roofs generate more cutting waste at the diagonal hips. Budget 15% extra instead of 10%.
What about underlayment and drip edge?
Underlayment is sold by the roll covering roughly 400–1,000 sq ft depending on type, so 1,677 sq ft of roof needs about two to four rolls. Drip edge follows the eave and rake lengths — measure the roof perimeter rather than the area.