Price per Square vs Price per Square Foot in Roofing
A roofing square is 100 square feet of roof surface, the unit the asphalt roofing industry uses to measure a roof (Asphalt Roofing Manufacturers Association, ARMA). To turn a price per square into a price per square foot, divide by 100; to go the other way, multiply by 100; and a bid's total divided by its number of squares gives its price per square. The arithmetic is the easy part. Two bids' unit prices compare only if they're measured on the same area, the roof's surface rather than the house's floor, and cover the same work.
This page is about the units. It doesn't give roofing prices, and how a roof is measured, from pitch to waste, is a separate subject, covered in how roofers measure a roof in squares. Why a hip roof and a gable roof over the same footprint and pitch come to the same area is shown in hip roof vs gable roof.
The conversions
Because a square is exactly 100 square feet, converting between the two units never needs a calculator: every step is a multiplication or division by 100.
| You have | You want | Do this | Example |
|---|---|---|---|
| A price per square | A price per square foot | Divide by 100 | Move the decimal point two places to the left |
| A price per square foot of roof | A price per square | Multiply by 100 | Move the decimal point two places to the right |
| A bid total and the number of squares | A price per square | Divide the total by the squares | For a bid on 28 squares, the total divided by 28 |
| A number of squares | Square feet of roof | Multiply by 100 | 28 squares is 2,800 square feet of roof |
| Square feet of roof | Squares | Divide by 100 | 2,655 square feet is 26.55 squares |
| A number of squares | Square meters | Multiply by 9.29 | 28 squares is about 260 square meters |
A square counts the roof, not the house
A square measures roof surface, and a pitched roof's surface is larger than the floor area under it. On a 6:12 roof, for example, the sloped surface is about 12% larger than the flat area it covers, before the overhangs at the eaves and rakes are added; the steeper the roof, the bigger the gap. So a bid quoted per square foot of the house's floor area isn't comparable with one quoted per square or per square foot of roof. Before converting, check which area each price is based on.
What has to match before two prices compare
The same unit price can buy different work. Before comparing a price per square on one bid with a price per square foot on another, check that they share:
- The area. Roof surface on both, not floor area on one.
- The scope behind the unit. Whether the unit price includes tear-off and disposal, underlayment, drip edge and flashings, vents and ridge, or whether those are separate lines.
- The square count. A bid's squares can run a little above the measured roof area: ARMA's manual notes that once the roof area is determined, the amount of shingles is adjusted for the trimming at valleys, roof penetrations and rake edges. Ask whether the count includes that allowance, and how much.
- The covering. A square of one product isn't a square of another; see the next section.
On our 2025 Woodland Hills re-roof, the roof measured about 2,655 square feet, 26.55 squares, and the bids were taken on 28 squares. The other places two quotes for the same roof part ways are in why roofing quotes differ.
Bundles, pieces and squares
Shingles are sold in bundles, and ARMA's glossary puts it at typically 3, 4 or 5 bundles per square, depending on the product. Owens Corning's product page for its TruDefinition Duration shingles, for example, lists 3 bundles, 64 shingles and 98.4 square feet of coverage per square at the shingle's exposure. So a count of bundles converts to squares only with the product's own figure.
Tile, underlayment and membranes are often quoted per square too, but each comes in its own units, pieces, rolls or sheets, so check the unit on every line rather than assuming it's the same as the shingle line.
Squares on permits and on our jobs
Squares aren't only a bidding unit. In the City of Los Angeles, the express re-roof permit application gives the number of squares, and the permit record's work description shows it, as in "(90) Squares"; more on reading that record is in checking that a re-roof permit was finaled and on the permit itself in roof permit in Los Angeles. Our own jobs, in squares:
- Canoga Park, 2021: 42 squares of composition shingle over the existing sheathing.
- Glendale, 2022: 28 squares of composition shingle, replacing concrete tile.
- Woodland Hills, 2025: about 2,655 square feet, bid at 28 squares, stripped to new plywood.
- Studio City, 2026: one square, about 100 square feet, under a working solar array.
Cali Energy holds California contractor license #1032379, with C-39 Roofing, B General Building and C-10 Electrical, the classification that covers solar. How we write a roofing estimate is on our roofing page.
Frequently asked
How many square feet are in a roofing square?
How do I convert a price per square to a price per square foot?
Is a roofing square the same as 100 square feet of my house?
How many bundles of shingles are in a square?
Why does my bid list more squares than my roof's area?
Related reading
Sources & methodology
Code sections, rules and figures on this page come from the primary sources below. Codes, local requirements and product terms change; each was verified October 9, 2026.
We'll give you the roof's area in squares and square feet
Call (323) 844-7777. We measure the roof itself, not the house, and tell you its area in squares and in square feet, so any bid on your roof can be compared line by line. Have ready the address, the bids you have, and a few photos of the roof; the area of a roof with several slopes, dormers or additions is only certain once it's measured.
Prepared by Cali Energy, October 9, 2026. This article is for general educational purposes only and is not legal, tax, financial, engineering, or utility advice. Rates, incentives, codes, permit requirements, equipment specifications, prices, and program terms may change; figures and timelines are estimates, not guarantees. Confirm current requirements with the applicable utility, AHJ, program administrator, manufacturer, or a licensed professional. See our Content Disclaimer. Cali Energy · 19201 Parthenia St, Unit E, Northridge, CA 91324 · CSLB #1032379 (B, C-10, C-39)