A roofing square is a unit of area equal to 100 square feet of roof surface. Roofers use it as shorthand, so a roof described as 30 squares has about 3,000 square feet of surface to cover. It is the standard unit for talking about roof size, ordering shingles and comparing estimates.
Why do roofers use squares instead of square feet?
Roofs are big, and the numbers add up fast. Saying "thirty squares" is quicker and less error-prone than saying "three thousand square feet" over and over across estimates, material orders and crew schedules. It also lines up with how shingles are sold, which makes ordering simpler.
You will hear the term constantly in the field. Our owner's posts about the day's work read like a list of squares, with jobs described by size: a 25 square roof here, a 37 square roof there, a 50 square roof that was a little steep, and a big 70 square roof at the other end of the scale. The number tells a crew roughly how long a roof will take and how much material has to show up.
How do you figure out how many squares a roof has?
The roof's surface area is not the same as the footprint of the house. A sloped roof has more surface than the floor beneath it. A rough path looks like this:
- Measure the roof surface of each plane (each flat face of the roof), either on site or from measurements taken safely from the ground or from aerial imagery.
- Multiply length by width on each plane to get its area in square feet.
- Add the planes together for the total area.
- Divide by 100 to get squares.
- Add extra for waste (see below), so the order covers cuts, starter courses and ridge pieces.
Steeper roofs have more surface for the same footprint, so pitch matters. Our short explainer on roof pitch shows why. Do not walk a roof to measure it yourself. Satellite measurements and a roofer's tape from a safe position are the usual approach.
What is a waste factor?
Shingles are cut around valleys, hips, edges and obstacles, and the offcuts are not all reusable. Roofers add a percentage on top of the measured squares to cover that, and a bigger roof is also a longer job, as covered in how long a roof replacement takes. The right allowance depends on how complicated the roof is. A plain gable roof wastes less than one with many valleys, dormers and hips. Ask your roofer how much waste is built into the order. The exact percentages differ by crew and product, so they are left to your estimate.
How many bundles are in a square?
Shingles are sold in bundles. For many common asphalt shingles, it typically takes three bundles to cover a square, but check the product, because some lines use different bundle sizes and some specialty shingles are packaged differently. The label on the bundle or the manufacturer's data sheet states the coverage.
| Term | Meaning |
|---|---|
| Square | 100 square feet of roof surface |
| Bundle | One package of shingles; many products need about three per square |
| Waste | Extra material ordered for cuts and trimming |
| Ridge cap | Separate product for hips and ridges, sold by linear foot or bundle |
Does a bigger roof always mean a bigger bill?
Squares drive material and labor, so size matters. They are not the only thing that does. Steepness, number of stories, how many valleys and penetrations the roof has, decking condition, and underlayment choice all change the price. That is why two houses with the same square count can come out differently. For how decking and code items can change an estimate, see why a roof estimate changes.
Frequently asked questions
How many square feet is one roofing square? One hundred square feet of roof surface.
How many squares is a typical house roof? It varies widely with the size of the house, the number of stories and the roof's shape. Rather than guess, have the roof measured.
Do squares include the waste? Not by default. A measured count is the surface of the roof. A material order adds waste on top. Ask how your estimate treats it.
Is a square the same as a bundle? No. A bundle is one package of shingles. A square is a unit of area. It often takes about three bundles to cover a square, but confirm for your product.
Can I measure my own roof? You can estimate from the ground or from online imagery, but do not climb the roof to measure. A roofer will measure safely and double-check.
Is the squares number on my estimate negotiable? It is a measurement, not a price. If the number looks off, ask your roofer to show the measurement or the diagram it came from.
Talk to us about your roof
See our services for what we install. Total Roof Protection OKC can measure your roof and walk you through the numbers on an estimate. Call 405-415-5841 to schedule an inspection. An inspection describes the roof and does not predict an insurer's decision.