Roof square footage calculator
Enter an address and get that roof’s square footage, roofing squares and shingle bundles in seconds — no tape measure, no ladder, no guessing at the pitch.
Free · No signup · Reads a 3D satellite model of the roof, not a database of guesses
Already have measurements?
Enter the roof area you measured, or the house footprint and its pitch, and get squares and shingle bundles with your own waste factor.
Roof size
Roof surface if you have it, footprint plus pitch if you do not.
Total sloped surface of the roof, including all planes and overhangs.
Extra material for cuts, hips, valleys, and starter. 10% simple, 15% typical, 20% complex.
2,200
Square feet of roof
22.0
Roofing squares
What to order
- With 15% waste
- 25.3 squares
- Squares to order (rounded up)
- 26
- Bundles (3 per square)
- 76
Bundles assume standard 3-tab or architectural shingles at 3 bundles per square. Heavier or specialty shingles run 4–5 bundles per square — check the coverage on the wrapper. Starter strip, hip-and-ridge cap, underlayment, drip edge and fasteners are ordered separately.
How to calculate roof square footage
A roof is always bigger than the house under it, because it slopes. The whole job is getting the sloped area, then turning it into the unit roofers actually buy in.
- 1
Look up the address
The fastest way, and the only one that measures the actual roof rather than inferring it: enter the address at the top of this page. A 3D satellite model of that house returns the sloped roof area in square feet — pitch already accounted for — plus the number of roof planes.
- 2
Or measure the footprint and multiply by the pitch
Measure the length and width of the house at ground level, including the overhangs, and multiply for the footprint in square feet. Then multiply by the pitch multiplier: 1.031 for 4/12, 1.118 for 6/12, 1.202 for 8/12, 1.302 for 10/12. A 1,600 sq ft footprint at 6/12 is 1,600 × 1.118 = 1,789 sq ft of roof.
- 3
Convert square feet to roofing squares
Divide the roof area by 100. One roofing square is 100 square feet of roof surface, and it is the unit every estimate, material order and insurance scope is written in. 1,789 sq ft is 17.9 squares.
- 4
Add waste before you order anything
Cuts at hips, valleys, rakes and penetrations mean you buy more than you install. Add 10% on a simple gable roof, 15% on a typical roof, and 20% on a cut-up roof with lots of valleys. 17.9 squares at 15% waste is 20.6 squares — order 21.
The one mistake to avoid. The square footage of a roof is not the square footage of the house. A 2,000 sq ft home with a 6/12 roof has roughly 2,236 sq ft of roof — and that gap is 2.4 extra squares, about seven bundles. Ordering off the listing size is how a crew ends up short on a Friday afternoon.
Square feet to roofing squares and bundles
Roof area converted to squares, then to what you actually order at a 15% waste factor.
| Roof area | Squares | Order (15% waste) | Bundles |
|---|---|---|---|
| 1,000 sq ft | 10.0 | 12 | 35 |
| 1,200 sq ft | 12.0 | 14 | 42 |
| 1,400 sq ft | 14.0 | 17 | 49 |
| 1,600 sq ft | 16.0 | 19 | 56 |
| 1,800 sq ft | 18.0 | 21 | 63 |
| 2,000 sq ft | 20.0 | 23 | 69 |
| 2,200 sq ft | 22.0 | 26 | 76 |
| 2,400 sq ft | 24.0 | 28 | 83 |
| 2,600 sq ft | 26.0 | 30 | 90 |
| 2,800 sq ft | 28.0 | 33 | 97 |
| 3,000 sq ft | 30.0 | 35 | 104 |
| 3,500 sq ft | 35.0 | 41 | 121 |
| 4,000 sq ft | 40.0 | 46 | 138 |
What a roofing square is
One roofing square is 100 square feet of roof surface. Every estimate, material order, supplier quote and insurance scope is written in squares rather than square feet, which is why converting is the first thing anyone does with a measurement. More on roofing squares.
Next
Roof replacement cost calculator — turn these squares into a price.
Roof pitch calculator — the multiplier behind the area.
Free roofing estimate template — write it up.
Hail damage lookup — check whether that roof has been hit.
Roof square footage questions, answered
Two ways. Measure the house footprint at ground level (length × width, including overhangs) and multiply by the pitch multiplier — 1.118 for a 6/12 roof, 1.202 for 8/12 — because a sloped roof is always bigger than the house under it. Or enter the address at the top of this page and read the sloped area straight off a 3D satellite model of that roof, with the pitch already accounted for.