A roofing square is a unit of measurement equal to 100 square feet of roof surface area. Roofers use squares to size jobs, order shingles, and quote prices: a roof with 2,000 square feet of surface is a 20-square roof, and materials are typically sold and priced per square.
Because the whole industry is built around the unit. Shingles are packaged so a set number of bundles covers one square. Suppliers price underlayment, and crews price labor, per square. When a contractor, a supplier, and an insurance adjuster all talk about the same roof, "squares" keeps everyone on the same number.
It also keeps estimates readable. "This is an 18-square roof" communicates the size of the job instantly — and multiplying 18 by a per-square price for materials and labor is the backbone of most roofing quotes.
| Roof surface area | Roofing squares |
|---|---|
| 1,000 sq ft | 10 squares |
| 1,500 sq ft | 15 squares |
| 1,850 sq ft | 18.5 squares |
| 2,000 sq ft | 20 squares |
| 2,750 sq ft | 27.5 squares |
| 3,400 sq ft | 34 squares |
Divide the roof's surface area in square feet by 100. The important detail: use the roof surface area — the sloped planes you would actually shingle — not the home's living area or footprint.
Shingles are sold in bundles sized so that a fixed number covers one square. For standard three-tab shingles and most architectural shingles, that is three bundles per square — so a 20-square roof needs roughly 60 bundles before waste. Some heavier or premium products pack four or more bundles per square; the coverage is printed on every bundle wrapper.
Real orders also add a waste factor — commonly around 10% on simple roofs and 15% or more on cut-up roofs with many hips and valleys — because shingles are trimmed at edges, ridges, and flashing details.
You can measure by hand — footprint, pitch multiplier, plane by plane — or let satellite measurement do it. SquaresForSales returns roof area in squares and square feet, estimated pitch, and facet count for any US address in under 30 seconds, with unlimited measurements for a flat $50/month or $499/year (save $101), starting with a 7-day free trial.
A roofing square is a unit of measurement equal to 100 square feet of roof surface area. It is the standard unit roofers use to size jobs, order materials, and quote prices. A roof with 2,400 square feet of surface area is a 24-square roof.
Exactly 100 square feet. To convert roof area to squares, divide the square footage by 100. For example, 1,750 sq ft of roof surface is 17.5 squares.
Typically three bundles per square for standard three-tab and most architectural shingles. Some heavier or premium products pack four or more bundles per square, so always check the coverage printed on the manufacturer's bundle before ordering.
No. Roof squares measure the sloped roof surface, not the home's living area. Because the roof is pitched and usually overhangs the walls, its surface area is larger than the footprint below it — so a 2,000 sq ft house does not have a 20-square roof.
Convenience and convention. Shingles, underlayment, and labor are all packaged, priced, and quoted per 100 sq ft, so working in squares keeps estimates, material orders, and supplier pricing in the same unit. Saying '18 squares' is faster and less error-prone than '1,800 square feet.'
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