Calculators / Roofing
Roofing Calculator
A 2,000 sq ft one-story house with a 6/12 roof has about 2,460 sq ft of roof, or 24.6 squares. With 10% waste, plan on 27.1 squares: 82 bundles of shingles at 3 bundles per square. Enter your house below.
How much roofing do you need?
| Squares before waste | 24.60 |
|---|---|
| Synthetic underlayment (10-square rolls) | 3 |
| Footprint used | 2,000 sq ft |
Want the installed price? See roof replacement cost: a typical 24.6-square architectural shingle roof costs $15,110, with most homeowners paying $9,160 to $24,850.
How much will it cost? Replacing an architectural shingle roof on a 2,000 sq ft one-story home typically costs $15,110, tear-off included. Roof replacement cost in your state
How to calculate roofing materials
Roof area = footprint × (1 + overhang) × pitch multiplier. A one-story 2,000 sq ft house with a 10% overhang and a 6/12 roof: 2,000 × 1.10 × 1.118 = 2,460 sq ft. For a two-story house, the footprint is the living area divided by 2.
Squares = roof area ÷ 100. Bundles = squares × (1 + waste) × bundles per square, rounded up. Underlayment = squares plus 10% for overlaps, in 10-square rolls.
Roof pitch multipliers
| Pitch | Multiplier | Angle | Roof area on a 1,000 sq ft footprint |
|---|---|---|---|
| 2/12 | 1.014 | 9.5° | 1,014 sq ft |
| 3/12 | 1.031 | 14.0° | 1,031 sq ft |
| 4/12 | 1.054 | 18.4° | 1,054 sq ft |
| 5/12 | 1.083 | 22.6° | 1,083 sq ft |
| 6/12 | 1.118 | 26.6° | 1,118 sq ft |
| 7/12 | 1.158 | 30.3° | 1,158 sq ft |
| 8/12 | 1.202 | 33.7° | 1,202 sq ft |
| 9/12 | 1.250 | 36.9° | 1,250 sq ft |
| 10/12 | 1.302 | 39.8° | 1,302 sq ft |
| 11/12 | 1.357 | 42.5° | 1,357 sq ft |
| 12/12 | 1.414 | 45.0° | 1,414 sq ft |
Roofing for common house sizes
One story, 6/12 pitch, 10% overhang and 10% waste, 3 bundles per square.
| House size | Roof area | Squares with waste | Bundles |
|---|---|---|---|
| 1,000 sq ft | 1,230 sq ft | 13.5 | 41 |
| 1,500 sq ft | 1,845 sq ft | 20.3 | 61 |
| 2,000 sq ft | 2,460 sq ft | 27.1 | 82 |
| 2,500 sq ft | 3,075 sq ft | 33.8 | 102 |
| 3,000 sq ft | 3,689 sq ft | 40.6 | 122 |
Common questions
What is a roofing square?
A square is 100 sq ft of roof. Shingles, underlayment and labor are usually priced per square.
How many bundles of shingles are in a square?
Most asphalt shingles, both 3-tab and architectural, come 3 bundles to a square. Some heavier designer shingles need 4 or 5 bundles per square, so check the wrapper.
How do I measure my roof without climbing on it?
Measure the house footprint from the ground, then use the pitch multiplier. To find the pitch, hold a level against a rafter in the attic, measure 12 in along the level, and measure straight up to the rafter: that number is the rise per 12 in.
Does this include ridge cap, starter strip and flashing?
No. Ridge cap, starter strip, drip edge and flashing depend on the length of the ridges, edges and valleys, not the area. Ask your supplier to figure them from the roof plan.
How much does a new roof cost?
For a 2,000 sq ft one-story house with architectural shingles, a typical installed price is $15,110, and most homeowners pay $9,160 to $24,850. Use the roof replacement cost calculator for your state, material and roof size.
How we calculated this
Pitch multipliers are √(1 + (rise ÷ 12)²), the same ones our roof replacement estimates use. We test the calculator against 155 worked examples, checked with a separate program. Sources.
Results are estimates. Dormers, valleys and skylights change the material count, so get a measured quote before you order.
Changelog
- : Published.
- : Formulas checked against 155 worked examples, verified with a separate program.
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