(440) 307-2060
How Many Square Feet Is a Square of Roof Shingles?
When you start planning a roofing project, one of the first things you’ll run into is the term “square”—and unless you’ve worked in construction or roofing before, it’s easy to get confused. What does a “square” mean in roofing? How many square feet is a square of roof shingles? And how do you figure out how many squares you need?
This guide breaks it all down into plain, simple language. Whether you’re replacing a few shingles, redoing an entire roof, or just want to understand how the math works, you’ll walk away with the knowledge you need to estimate roofing materials, measure your roof, and talk confidently with a roofing contractor.
What Is a Square in Roofing?
Let’s start with the basics.
In roofing, one “square” equals 100 square feet of roof area.
This is an industry shorthand used to simplify ordering and estimating materials. So when a contractor says your roof is 20 squares, they mean your roof has approximately 2,000 square feet of surface area.
The term “square” doesn’t refer to the shape of the roof or the layout of the shingles. It’s simply a unit of measurement.
Why Roofing Is Measured in Squares Instead of Square Feet
Measuring in “squares” simplifies communication in the roofing industry.
For example, instead of saying:
“We need 2,300 square feet of shingles, 2,300 square feet of underlayment, and 2,300 square feet of ice and water shield…”
A contractor can say:
“We need 23 squares.”
This makes estimating, ordering, and installing materials more efficient. Manufacturers bundle and sell shingles in groupings based on this measurement. Most shingle products are packaged so that three bundles equal one square—but more on that in a minute.
How Many Square Feet in a Square of Roof Shingles?
✅ Answer: 100 square feet
So if someone says they bought 10 squares of shingles, that means they have enough material to cover 1,000 square feetof roof surface.
This measurement takes into account only the area that the shingles will cover—not extra material for overlaps, ridges, valleys, or waste. You’ll usually buy more than the exact number of squares to ensure full coverage and allow for cutting or error.
Bundles vs. Squares: What’s the Difference?
Now let’s talk about bundles.
Shingles are packaged in bundles. A bundle is a smaller package of shingles. Most brands sell shingles in a way that three bundles equal one square, but the exact number depends on the style and weight of the shingles.
Here’s how it works:
| Shingle Type | Bundles per Square | Square Feet per Bundle |
|---|---|---|
| 3-tab shingles | 3 | ~33.3 sq ft |
| Architectural shingles | 3–4 | ~25–33 sq ft |
| Designer shingles | 4 or more | ~20–25 sq ft |
So when you go to buy shingles:
- If you need 10 squares, and the shingles come 3 bundles per square, you’ll need 30 bundles
- If you’re using a heavier or premium shingle, it might take 4 bundles per square, so you’d need 40 bundles
Always check the packaging to confirm how much area each bundle covers.
How to Calculate the Number of Squares on Your Roof
To figure out how many squares you need, you first need to know the square footage of your roof.
Step 1: Measure Your Roof’s Area
Start by measuring the length and width of each roof section. Multiply them to get the area of each section.
Let’s say your roof has two rectangles:
- One section is 30 feet by 20 feet → 600 sq ft
- Another section is 40 feet by 10 feet → 400 sq ft
- Total area = 1,000 sq ft
Now divide that number by 100 to get the number of squares:
1,000 ÷ 100 = 10 squares
Step 2: Add Waste Factor
Roofing projects always include some waste—due to cutting, fitting, or errors. A waste factor of 10% to 15% is standard.
So for a 10-square roof:
- Add 10% waste → 10 x 1.10 = 11 squares
- Add 15% waste → 10 x 1.15 = 11.5 squares
Round up to the nearest half or full square to be safe.
Roof Complexity Affects Square Footage
Roofs are not always simple rectangles. The more complex your roof is—hip roofs, dormers, steep slopes, valleys—the more surface area it has. And that means more squares.
Here’s how complexity impacts measurement:
| Roof Type | Complexity Level | Waste Factor |
|---|---|---|
| Gable Roof | Simple | 10% |
| Hip Roof | Moderate | 12–15% |
| Multi-Level Roof | Complex | 15–20% |
What About Roof Pitch?
Pitch refers to the steepness of the roof, and it also affects square footage. A steeper roof has more surface area than a flatter roof, even if the footprint is the same.
To adjust for pitch, use a pitch multiplier.
Pitch Multipliers by Roof Pitch:
| Roof Pitch | Multiplier |
|---|---|
| 3/12 | 1.03 |
| 4/12 | 1.05 |
| 5/12 | 1.08 |
| 6/12 | 1.12 |
| 7/12 | 1.16 |
| 8/12 | 1.20 |
| 9/12 | 1.25 |
| 10/12 | 1.30 |
So, if your home has a 1,000-square-foot base with a 6/12 pitch:
1,000 x 1.12 = 1,120 sq ft of roof
1,120 ÷ 100 = 11.2 squares
Add 10% waste = 12.3 squares → round up to 13 squares
How to Measure a Roof Without Climbing
You don’t have to get on the roof to measure it. Here are a few options:
1. Use Your Home’s Blueprints or Property Records
These may show roof dimensions or square footage.
2. Use Satellite Tools or Aerial Estimators
There are many free and paid apps and services that use satellite imagery to estimate your roof size.
3. Estimate from Ground Level
If your roof is relatively flat, you can measure the perimeter from the ground and factor in overhangs, then adjust for pitch.
Common Questions About Roofing Squares
Can I buy half a square of shingles?
Most suppliers don’t sell “half squares,” but you can buy individual bundles. If one bundle covers about 33 square feet, you can buy just one or two if you need to patch a small area.
How much does a square of shingles cost?
Prices vary by material and region:
- 3-tab asphalt shingles: $90–$120 per square
- Architectural shingles: $110–$160 per square
- Designer or premium shingles: $200–$400+ per square
This is material only and does not include underlayment, flashing, nails, or labor.
How many nails per square?
About 320 nails are needed per square of asphalt shingles (assuming four nails per shingle and roughly 80 shingles per square).
Why It’s Important to Know How Many Squares You Need
Understanding how squares work helps you:
- Communicate effectively with contractors
- Budget your project realistically
- Avoid over- or under-buying materials
- Compare estimates more accurately
- Plan for future maintenance
It’s also handy if you want to double-check a roofing quote or plan a DIY repair.
Roofing Materials and Their Coverage Per Square
Different roofing materials cover different areas per unit and may require more or fewer bundles per square.
| Material | Bundles/Square | Weight/Square |
|---|---|---|
| 3-tab Asphalt Shingles | 3 | ~200–250 lbs |
| Architectural Shingles | 3–4 | ~250–300 lbs |
| Wood Shakes | Varies | ~400 lbs |
| Metal Panels | Varies | ~100–150 lbs |
| Slate Tiles | Varies | ~700–1,000 lbs |
Always verify manufacturer specs for exact coverage and weight.
Waste Factor: Why It Matters More Than You Think
It’s tempting to try to save money by not ordering extra material—but this often backfires.
Here’s why adding a waste factor is smart:
- Shingles need to be trimmed at edges and valleys
- Mistakes happen
- You may need to match color later
- Shingle lots can have slight variations
Ordering just enough is risky—running out of material mid-job causes delays and mismatched repairs.
