Quick definition
A unit of roof area equal to 100 square feet, used to measure roofs and order materials.
Roofers don't price jobs by the square foot. They use the square, a unit of 100 square feet of roof surface, and almost every roofing estimate is built on it.
How many bundles are in a square?
Most asphalt shingles are packaged three bundles to a square. Some heavier designer shingles take four or five bundles per square. Each bundle's wrapper states its coverage.
Why do squares matter?
- Material is ordered by the square.
- Labor and tear-off are often priced per square.
- Insurance and contractor estimates use squares, so they can be compared line by line.
What is a roofing square?
A roofing square is 100 square feet of roof surface. A roof with 2,500 square feet of surface is a 25-square roof. The measure is roof surface, not the house's floor area or footprint, so a steep roof has more squares than a flat one over the same house.
How are squares calculated?
1. Measure the area of each roof plane, or multiply the footprint by the pitch multiplier. 2. Add the planes together for the total roof area. 3. Divide by 100 to get squares. 4. Add a waste factor for cutting at hips, valleys, rakes and starter courses.
Worked example
| Step | Value |
|---|---|
| Footprint, including overhangs | 2,000 sq ft |
| Pitch | 6:12 (multiplier 1.118) |
| Roof surface | 2,236 sq ft |
| Squares | 22.4 |
| Plus 10% waste | about 24.6 squares to order |
:::technical-note Waste factors are commonly around 10 to 15 percent, and higher on complex roofs with many hips, valleys and dormers. Measurement reports and estimators set the figure for each roof. :::
What it means for you
What Square means for insurance adjusters
Insurance estimates price roof removal and replacement per square and add a waste factor to the measured area. Differences in measured squares or waste are a common reason estimates and contractor quotes don't match.
Frequently asked questions
Sources
- Residential Asphalt Roofing Manual. ARMA.
Tier 2 authority 路 industry - Shingle manufacturer bundle coverage specifications. Technical Reference.
Tier 1 authority 路 manufacturer - The NRCA Roofing Manual: Steep-slope Roof Systems. NRCA.
Tier 2 authority 路 industry