Roofing Calculator
Enter your roof footprint and pitch and get the full material list: squares, shingle bundles, underlayment, starter, ridge cap, and nails, plus a 2026 cost estimate. It is free to use and needs no signup.
The flat area the house covers (its outline on the ground), not the sloped roof. The pitch below converts it to true roof area.
Not sure? A typical house roof is 4:12 to 8:12. A flat roof is 0.
10% for a simple gable, 15% standard, 20%+ for a cut-up hip roof with lots of valleys.
Installed price for one square (100 sq ft). Materials only run far less; see the cost table below.
Illustration, not to scale
Illustration, not to scale
Roofing squares (with 15% waste)
25.7squares= 78 bundles
2,000 sq ft footprint × 1.118 (pitch) = 2,236 sq ft of roof (22.4 squares before waste).
A material list to price and order from, not a substitute for measuring the roof. Field-measure or take off the plan before you buy.
You estimated this from a rectangle.
A real roof has hips, valleys, and dormers a flat footprint misses. In Easy Takeoffs you measure every roof plane off the plan PDF to scale, apply the pitch as the slope factor, and get true squares and bundle counts off the drawing, not a guess. 14-day trial, no card.
How much does a new roof cost?
A new asphalt shingle roof runs about $4 to $9 per square foot installed in 2026, so a typical 2,000 square foot roof costs roughly $8,000 to $18,000. Labor is 40 to 60 percent of that, tear-off of the old roof adds more, and metal, tile, or slate cost more. Prices vary by region and roof complexity, so treat these as a starting point and get a local quote.
What a new roof costs by material (2026)
| Material | Per sq ft, installed | Per square (100 sq ft) |
|---|---|---|
| 3-tab asphalt | $3.50 to $8.75 | $350 to $875 |
| Architectural asphalt | $4.50 to $9.00 | $450 to $900 |
| Corrugated metal | $6 to $12 | $600 to $1,200 |
| Standing-seam metal | $10 to $18 | $1,000 to $1,800 |
| Concrete or clay tile | $10 to $25 | $1,000 to $2,500 |
| Slate | $10 to $30 | $1,000 to $3,000 |
2026 US averages, installed (materials + labor), from This Old House, Fixr, and Modernize. Labor is 40 to 60 percent of the total, and tearing off the old roof adds $0.50 to $1.50 per sq ft (more for multiple layers or tile). Confirm with a local contractor.
Cost by roof size (asphalt shingles, installed, 2026)
| Roof size | Squares | Installed cost |
|---|---|---|
| 1,000 sq ft | 10 | $4,000 to $9,000 |
| 1,500 sq ft | 15 | $6,000 to $13,500 |
| 2,000 sq ft | 20 | $8,000 to $18,000 |
| 2,500 sq ft | 25 | $10,000 to $22,500 |
| 3,000 sq ft | 30 | $12,000 to $27,000 |
By ROOF size, not house footprint: a 2,000 sq ft house has more than 2,000 sq ft of roof once you add the pitch (about 12 percent more at 6:12) and the overhangs. Higher-end materials scale up from the per-square table above.
What materials do you need to roof a house?
A shingle roof is more than shingles. For each square (100 square feet) you need about 3 bundles of shingles and a share of underlayment, plus starter strip and ridge cap along the roof edges, and nails to fasten it all. The calculator totals each one from your footprint and pitch.
Roofing materials at a glance
| Material | How it is sold | Coverage |
|---|---|---|
| Shingles | By the bundle | 3 bundles per square (each about 33.3 sq ft) |
| Underlayment | By the roll | Synthetic about 10 squares; #15 felt 4; #30 felt 2 |
| Starter strip | By the bundle | About 110 linear feet, along the eaves and rakes |
| Ridge & hip cap | By the bundle | About 20 to 25 linear feet, along ridges and hips |
| Nails | By the box | About 320 per square (480 for high wind); ~980 per 5 lb box |
Standard 3-tab and architectural shingles are both 3 bundles per square; premium designer lines run 4 to 5. Starter and cap are edge quantities, so they depend on your roof shape, not just its area.
How do you measure a roof for shingles?
You measure a roof by planes. Find the length and width of each roof plane, multiply to get its footprint, then apply the pitch slope factor for the true surface. Add the planes together and divide by 100 for squares.
- 1
Sketch the roof and split it into rectangles, one per plane (each side of a gable, each section of a hip).
- 2
Measure the length and width of each plane in feet, from the ground, a ladder, or a plan.
- 3
Multiply length by width for each plane, then multiply by the pitch slope factor for the true sloped area.
- 4
Add the planes together and divide by 100 for roofing squares, then add 10 to 20 percent for waste.
How do you calculate roofing squares?
Roofing is measured in squares, and one square is 100 square feet of roof. Multiply your footprint by the pitch slope factor to get the true roof area, divide by 100 for squares, then add 10 to 20 percent for waste before you order. Each material then comes off the squares or the roof edges. Here is the math, with a worked example.
- Roof area
- footprint area × the pitch slope factor
- Squares
- roof area ÷ 100 (one square = 100 sq ft)
- Shingle bundles
- squares × 3, plus waste, rounded up (3 bundles per square)
- Underlayment rolls
- squares ÷ 10 for synthetic (÷ 4 for #15 felt), plus waste, rounded up
- Starter & ridge cap
- edge length ÷ the product coverage (starter about 110 ft per bundle, cap about 20)
- Nails
- about 320 per square at 4 nails per shingle (480 at 6 for high wind)
Ordering adjustments
Order to the waste allowance, not the bare roof area: 10 percent for a simple gable, 15 percent for hips and valleys, up to 20 percent for a complex, cut-up roof. Round every material up to whole bundles, rolls, and boxes, and keep the roof area itself un-inflated so you can check it against the plan.
Worked example
2,000 sq ft footprint, 6:12 pitch, architectural shingles, 15% waste
- 2,000 × 1.118 = 2,236 sq ft of roof
- 2,236 ÷ 100 = 22.36 squares
- Add 15% waste: 22.36 × 1.15 = 25.7 squares
- Bundles: 25.7 × 3 = 77.1, round up to 78
Roofing reference tables
Shingle and underlayment coverage
| Item | Coverage |
|---|---|
| Shingle bundle | About 33.3 sq ft (3 per square) |
| Synthetic underlayment roll | About 10 squares (1,000 sq ft) |
| #15 felt roll | About 4 squares (400 sq ft) |
| #30 felt roll | About 2 squares (200 sq ft) |
| Starter strip bundle | About 110 linear feet |
| Ridge & hip cap bundle | About 20 to 25 linear feet |
| Roofing nails | About 320 per square (~980 per 5 lb box) |
Coverage from GAF, Owens Corning, and IKO spec sheets. Confirm the exact figure on your product wrapper.
Waste allowance by roof complexity
| Roof | Waste |
|---|---|
| Simple gable, no valleys | 10% |
| Hip roof or a few valleys | 15% |
| Complex, cut-up, many dormers | 15 to 20% |
Order 1 to 2 extra bundles from the same color lot for future repairs.
Shingle lifespan by type
| Shingle | Typical lifespan |
|---|---|
| 3-tab asphalt | 15 to 20 years |
| Architectural asphalt | 25 to 30 years |
| Metal | 40 to 70 years |
| Tile or slate | 50 to 100 years |
Actual life depends on climate, ventilation, and installation quality.
Roofing Calculator Questions
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