What Is a Roofing Square?
One roofing square equals 100 square feet of roof surface. Shingles, underlayment and labor are all priced per square, so knowing your square count is the key to reading any roofing estimate. Full explanation: What is a square in roofing?
How to Calculate Roofing Squares
Measure the footprint
Length × width of the house, plus the eave overhang on every side.
Apply the pitch
Multiply by the pitch factor — 1.118 for a 6/12 roof. Find yours with the roof pitch calculator.
Add waste
10% for simple gables, about 15% for hip roofs, more for complex roofs.
Divide by 100
The result is your square count. Multiply by 3 for bundles of standard architectural shingles.
Pitch Multipliers
| Pitch | Multiplier | Pitch | Multiplier |
|---|---|---|---|
| 3/12 | 1.031 | 8/12 | 1.202 |
| 4/12 | 1.054 | 9/12 | 1.250 |
| 5/12 | 1.083 | 10/12 | 1.302 |
| 6/12 | 1.118 | 11/12 | 1.357 |
| 7/12 | 1.158 | 12/12 | 1.414 |
Materials Per Square at a Glance
- Shingles: usually 3 bundles per square for standard architectural shingles (some heavier designer lines use 4–5).
- Underlayment: synthetic rolls cover roughly 10 squares; #15 felt about 4; #30 felt about 2. Compare them in our roofing underlayment types guide.
- Starter strip and drip edge: run the full perimeter of the eaves and rakes.
- Ridge cap: covers every ridge and hip.
- Self-adhered membrane: valleys, penetrations and low-slope areas — see ice and water shield costs.
Want to turn squares into dollars? Read cost of asphalt shingles per square or try the roof cost calculator.
Frequently Asked Questions
How many bundles of shingles are in a square?
Most standard architectural shingles come 3 bundles per square. Some heavier premium shingles need 4 or 5 — always check the wrapper.
How much is a square of shingles?
Material alone is commonly about $100–$200 per square for architectural shingles; installed prices in Austin typically run around $450–$650 per square. See our price per square guide.
What waste factor should I use?
About 10% for a simple gable roof and 15% for a hip roof. Roofs with many valleys, dormers or turrets can need 18–20%.
Can I measure my roof from the ground?
Yes, for an estimate: measure the house footprint, add overhangs and apply the pitch multiplier. A roofer measures each plane for an exact order.