How to use the roof cost calculator
You don't need to climb on the roof. Measure the outside of your house (or look up the footprint on your property record), choose your roof pitch and style, and the calculator converts that footprint into true roof surface area.
- Pitch is the rise in inches per 12 inches of run. Most US homes sit between 4/12 and 8/12. If you are not sure, keep 6/12.
- Roof style changes waste and labor: hip roofs and roofs with valleys and dormers take more cutting and time.
- Tear-off layers: most codes allow a maximum of two shingle layers, and nearly all roofers now recommend a full tear-off.
How roof area and squares are calculated
Roof area = Footprint × Pitch factor
Squares = Roof area ÷ 100
Shingle bundles = Squares × (1 + Waste) × 3
A roofing square is 100 sq ft of roof, and roofers price jobs per square. The pitch factor accounts for slope: a 6/12 roof has 11.8% more surface than its flat footprint, and a 12/12 roof has 41% more.
| Pitch | Multiplier | Pitch | Multiplier |
|---|---|---|---|
| 3/12 | 1.031 | 7/12 | 1.158 |
| 4/12 | 1.054 | 8/12 | 1.202 |
| 5/12 | 1.083 | 10/12 | 1.302 |
| 6/12 | 1.118 | 12/12 | 1.414 |
Roof replacement cost by material (2026)
Prices are per square foot of roof surface, installed, before tear-off. Multiply by 100 for the price per square.
| Material | Installed / sq ft | Lifespan |
|---|---|---|
| Asphalt 3-tab | $3.20–$4.80 | 15–20 yrs |
| Architectural shingles | $3.60–$5.60 | 25–30 yrs |
| Exposed-fastener metal | $5.50–$9 | 30–45 yrs |
| Standing seam metal | $9–$15 | 40–70 yrs |
| Cedar shake | $7.50–$13 | 25–40 yrs |
| Concrete tile | $9–$15 | 40–50 yrs |
| Clay tile | $14–$24 | 50–100 yrs |
| Slate | $17–$32 | 75–150 yrs |
| Flat roof TPO / EPDM | $5.50–$10 | 20–30 yrs |
Tearing off and hauling away the old roof adds $0.90–$1.40 per sq ft per layer. Steep roofs (8/12 and up) cost more because crews need extra safety equipment and work slower.
How to avoid overpaying for a new roof
- Get at least three written quotes that list the squares, material brand and line, underlayment type and the tear-off.
- Ask about decking replacement pricing up front. Rotten plywood is the most common surprise charge.
- Check your insurance. Storm or hail damage may be covered — call your insurer before signing with a roofer.
- Compare warranties, both the manufacturer's material warranty and the contractor's workmanship warranty.
- Look for off-season deals. Late fall and winter (where weather allows) are quieter months for many roofers.
Roofing cost by state
Replacing an architectural-shingle roof (50×30 ft house, 6/12 gable) — estimated cost by state. Figures use the same assumptions as the calculator above.
| State | Low | High | vs. US avg |
|---|---|---|---|
| US average | $8,372 | $13,022 | — |
| Alabama | $7,283 | $11,330 | -13% |
| Alaska | $10,464 | $16,278 | +25% |
| Arizona | $8,037 | $12,502 | -4% |
| Arkansas | $7,200 | $11,199 | -14% |
| California | $10,213 | $15,887 | +22% |
| Colorado | $8,623 | $13,413 | +3% |
| Connecticut | $9,544 | $14,846 | +14% |
| Delaware | $8,706 | $13,543 | +4% |
| District of Columbia | $9,627 | $14,976 | +15% |
| Florida | $7,953 | $12,371 | -5% |
| Georgia | $7,618 | $11,850 | -9% |
| Hawaii | $11,050 | $17,190 | +32% |
| Idaho | $7,869 | $12,241 | -6% |
| Illinois | $9,209 | $14,325 | +10% |
| Indiana | $7,953 | $12,371 | -5% |
| Iowa | $7,953 | $12,371 | -5% |
| Kansas | $7,786 | $12,111 | -7% |
| Kentucky | $7,702 | $11,981 | -8% |
| Louisiana | $7,534 | $11,720 | -10% |
| Maine | $8,372 | $13,022 | 0% |
| Maryland | $8,539 | $13,283 | +2% |
| Massachusetts | $10,046 | $15,627 | +20% |
| Michigan | $8,372 | $13,022 | 0% |
| Minnesota | $8,958 | $13,934 | +7% |
| Mississippi | $7,032 | $10,939 | -16% |
| Missouri | $8,204 | $12,762 | -2% |
| Montana | $8,037 | $12,502 | -4% |
| Nebraska | $7,786 | $12,111 | -7% |
| Nevada | $8,706 | $13,543 | +4% |
| New Hampshire | $8,706 | $13,543 | +4% |
| New Jersey | $9,795 | $15,236 | +17% |
| New Mexico | $7,618 | $11,850 | -9% |
| New York | $10,046 | $15,627 | +20% |
| North Carolina | $7,451 | $11,590 | -11% |
| North Dakota | $8,037 | $12,502 | -4% |
| Ohio | $8,120 | $12,632 | -3% |
| Oklahoma | $7,367 | $11,460 | -12% |
| Oregon | $8,874 | $13,804 | +6% |
| Pennsylvania | $8,623 | $13,413 | +3% |
| Rhode Island | $9,209 | $14,325 | +10% |
| South Carolina | $7,367 | $11,460 | -12% |
| South Dakota | $7,534 | $11,720 | -10% |
| Tennessee | $7,534 | $11,720 | -10% |
| Texas | $7,702 | $11,981 | -8% |
| Utah | $8,037 | $12,502 | -4% |
| Vermont | $8,539 | $13,283 | +2% |
| Virginia | $8,037 | $12,502 | -4% |
| Washington | $9,209 | $14,325 | +10% |
| West Virginia | $7,618 | $11,850 | -9% |
| Wisconsin | $8,455 | $13,153 | +1% |
| Wyoming | $7,786 | $12,111 | -7% |
Frequently asked questions
How much does it cost to replace a roof in 2026?
Most homeowners pay about $8,000–$18,000 to replace an asphalt shingle roof on an average single-family home. Metal, tile and slate cost two to five times more. Your state, roof size, pitch and complexity change the price a lot.
How many squares is my roof?
Take your home’s footprint including overhangs, multiply by the pitch factor (1.118 for a 6/12 roof) and divide by 100. A 50×30 ft house (1,500 sq ft) with 12-inch overhangs and a 6/12 roof comes to about 18.6 squares.
How many bundles of shingles are in a square?
Most architectural and 3-tab shingles come three bundles to a square (100 sq ft). Some heavy designer shingles need four or five bundles per square.
Is a metal roof worth the extra cost?
Metal costs about two to three times more than asphalt up front, but it can last 40–70 years compared with 20–30, and it may lower insurance premiums in hail- and wildfire-prone areas.
Can I put new shingles over my old roof?
Many codes allow one overlay (a maximum of two layers), but it adds weight, hides damaged decking and can shorten shingle life and void some warranties. Most roofers recommend a full tear-off.
How long does a roof replacement take?
Most asphalt shingle roofs on a typical home are replaced in one to three days. Tile, slate and complex roofs can take a week or more.