What Is a Roofing Square? (And Why Roofers Use It)
TL;DR
A roofing square is a standard unit roofers use to measure roof size. One square = 100 sq. ft. Most asphalt shingles take 3 bundles per square. So if your roof is 20 squares, that’s 2,000 sq. ft. (about 60 bundles). Roofers use squares to figure out how much material you’ll need, how long the job takes, and what it will cost.
What Does a Roofing Square Mean?
A “roofing square” is just roofer-speak for 100 square feet of roof. Imagine a section that’s 10 ft. by 10 ft.—that’s one square. Contractors talk in squares because it lines up perfectly with how shingles are packaged and sold. Instead of saying, “We need 2,500 square feet of shingles,” they can just say “25 squares.” Simple.
A Little History: Why Squares, Not Square Feet?
This goes way back. Roofing materials—especially asphalt shingles—have long been bundled to cover about 100 square feet. It kept loads manageable for workers to carry up ladders and also made it easy for suppliers to package and sell. Over time, the 100-sq.-ft. “square” became the industry standard. It’s still used today, even with modern architectural and luxury shingles.
The Math Behind Roofing Squares
Here’s the breakdown:
One square = 100 sq. ft.
Bundles per square: Most asphalt shingles = 3 bundles per square. Heavy shingles may need 4–5.
Example: A roof that’s 2,400 sq. ft. ÷ 100 = 24 squares. × 3 bundles = 72 bundles.
Waste factor: Add 10–15% more for valleys, hips, dormers, and cut-offs.
So if your contractor says your home is 25 squares, that means the roof covers about 2,500 sq. ft., which will take around 75 bundles of shingles—plus extras for waste.
Roofing Squares in Real Life
Small ranch home: 15–18 squares
Average PA/NJ two-story: 20–25 squares
Large custom home: 30+ squares
That’s why when homeowners ask us, “How big is my roof?” we usually give the answer in squares instead of just square feet.
FAQs
How many bundles in a roofing square?
Usually 3 bundles per square for asphalt shingles. Heavier luxury shingles may take 4 or more. Always check the label.
What does a square mean in roofing?
It’s the standard measure: 1 square = 100 sq. ft.
How much is 1 square on a roof?
One square = 100 sq. ft., which usually equals about 3 bundles of shingles.
How big is 20 squares of roofing?
That’s 2,000 sq. ft.—right around the average roof size for many homes in PA and NJ.
How to calculate a roof square?
Measure each roof plane (length × width). Add up the square footage of all sections. Divide by 100. That’s your number of squares.
How much do roofers get a square?
Prices vary, but in PA/NJ/DE, asphalt shingles usually cost $350–$700 per square installed. Metal, slate, or specialty roofs run higher.
How many squares is a 10x12 roof?
10 × 12 = 120 sq. ft. ÷ 100 = 1.2 squares. Round up to 2 squares to cover material needs.
Roofing Square Conversion Table
Squares | Square Feet | Bundles (3 per sq.) | Typical Installed Cost (Asphalt)* |
|---|---|---|---|
10 | 1,000 sq. ft. | ~30 bundles | $3,500 – $7,000 |
20 | 2,000 sq. ft. | ~60 bundles | $7,000 – $14,000 |
30 | 3,000 sq. ft. | ~90 bundles | $10,500 – $21,000 |
*Prices vary depending on pitch, complexity, and material type.
Why This Matters for Homeowners
Knowing what a roofing square is helps you avoid confusion when reading estimates. If one roofer says your home is 22 squares, you know that’s 2,200 sq. ft. and about 66 bundles of shingles. It also lets you compare bids more accurately and spot estimates that might be leaving out waste or complexity.
Need Help Figuring Out Your Roof Size?
If you’re in Pennsylvania, New Jersey, or Delaware, Paragon Exterior can measure your roof and give you a straight-forward estimate—no confusing jargon. Whether it’s repair, replacement, or a new installation, we’ll make sure you understand exactly what you’re paying for.
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