Free roofing cost calculator. Enter roof size, pitch, material and tear-off to estimate replacement cost per square foot and total.
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Enter your roof area in square feet, the roof pitch, the roofing material and whether the old roof must be removed. The calculator multiplies your roof area by the pitch factor to get the real covered area (a steep roof has more surface than a flat one), adds your waste allowance, then multiplies by the installed rate per square foot for the chosen material, which already includes labor. If you selected tear-off, it adds 1.25 per square foot of roof area for removal and disposal. The total and the cost per roofing square (100 sq ft) are the two numbers to compare against contractor bids. Results are estimates for budgeting, not professional quotes.
Roof replacement pricing starts from the actual surface of the roof, not the size of the house. The covered area is roof area × pitch factor × (1 + waste allowance), so cuts and overlaps do not surprise you later. That area is multiplied by the installed rate for your material, which covers materials and labor in one number, and the tear-off line is added when the old roof must come off.
Worked example: an 1800 sq ft roof with a medium 6:12 pitch (factor 1.12), 10% waste and asphalt shingles at 4.50 installed per sq ft gives a covered area of 1800 × 1.12 × 1.10 = 2217.6 sq ft. Material and labor come to 2217.6 × 4.50 = 9979.20. Tear-off at 1.25 per sq ft of roof area adds 1800 × 1.25 = 2250. The total is 12229.20, which is 679.40 per square (100 sq ft). Run your own numbers, then ask every contractor to break their bid into the same lines so you can compare like with like.
A roofing square is the contractor's unit of measure: exactly 100 square feet of roof surface. When a roofer says your job is 22 squares, they mean 2200 square feet of covered roof area, including the slope and waste, not 2200 square feet of living space.
This is why roof area is different from home square footage. The living area ignores slope, eaves and overhangs, while the roof surface grows with every one of them. A 2000 sq ft house with a medium-pitch roof and normal overhangs can easily have a roof surface of 2300 to 2600 square feet, and a steep roof pushes that higher still. Always price from the roof surface, never from the floor plan.
Installed rates per square foot (materials plus labor) drive the biggest swing in any roof replacement cost calculator. Asphalt shingles at 4.50 are the budget standard with a 20 to 30 year lifespan, and architectural shingles, a thicker premium asphalt, cost more upfront but usually win on value per year of service. Metal at 11.00 runs roughly double to triple the asphalt price, but the metal roof cost vs shingles question usually settles on lifespan: a metal roof lasts 40 to 70 years, so it can outlive two asphalt roofs while shedding snow and reflecting heat. Clay or concrete tile at 13.00 is the heavyweight option with a 50+ year lifespan, though many homes need structural checks first. Wood shake at 9.00 suits certain styles but needs more maintenance and lasts 20 to 40 years. Flat or EPDM at 7.00 is the go-to for low-slope roofs where shingles cannot be used.
Does roof pitch affect cost? Yes, twice over: a steeper roof has more surface area, and crews work slower and safer on it, which pushes roofing labor cost up. This calculator uses five bands: flat (2 percent or less) 1.00, low (3:12) 1.03, medium (6:12) 1.12, steep (9:12) 1.25 and very steep (12:12) 1.41. Those factors come from the geometry of the slope itself, which is why they show up in every serious roof pitch multiplier table.
A steep roof can need 25% more material than a flat roof of the same footprint, and labor often carries a similar premium because of staging and safety. If you are between two bands, pick the steeper one for a conservative estimate.
The most accurate input is a real roof measurement: length times width of each plane, added together. If you only know the home's square footage, start from that number and add at least 10 to 15% for slope and overhangs on a simple roof, more for complex or steep ones. Many contractors now measure from satellite imagery, so you can also ask a roofer for their square count before you sign anything.
Walk-around clues help too: count the planes, note dormers and valleys (each adds cutting waste), and check how many layers of old roofing are on the roof, since two layers force a tear-off. When in doubt, measure slightly high; an estimate that comes in under the bid is far more useful than one that hides the gap.
Can you put new shingles over old shingles? In many areas, yes, once. An overlay skips the tear-off charge entirely and is faster, but it adds weight, hides damaged decking, and most manufacturers shorten the warranty on an overlay. Two existing layers always require a full tear-off.
How much does tear-off add? In this calculator, 1.25 per square foot of roof area, so 2250 on an 1800 sq ft roof. The real price of skipping it is risk: rotted decking discovered mid-job turns a 2250 line into emergency decking charges at full contractor rates. When the old roof is near the end of its life or the decking condition is unknown, tear-off is the safer money.
A full replacement is rarely the only option. Localized repairs are enough when damage is confined: a few missing shingles after a storm, one leaking valley, or flashing that has pulled away. Patch those and keep the roof's remaining years.
Replacement becomes the honest answer when problems are widespread: curling or cracked shingles across multiple slopes, granule loss that leaves bald patches, sagging between rafters, daylight through the boards in the attic, or a roof past its material's expected lifespan. If a repair quote passes 30 to 40% of the replacement estimate this calculator gives, replacement usually wins on total cost of ownership.
Get three itemized bids and compare them line by line against this calculator's breakdown; any bid far below the estimate is probably cutting corners on underlayment or flashing. Ask about timing: what time of year is cheapest to replace a roof? Late winter and early spring are typically the slow season in most climates, and some roofers price more keenly when crews are idle, while peak storm season is the worst time to negotiate.
Material choice is the other lever. Architectural shingles give the best cost per year of service for most homes, and if your roof has a single aging layer, a permitted overlay can save the whole tear-off line. Finally, ask whether decking is priced per sheet with a cap in the contract, so a few bad boards cannot become an open-ended charge.
Does homeowners insurance cover roof replacement? Usually only when the damage is sudden and accidental, like hail, wind or a fallen tree. Insurers pay for storm damage to a roof, not for a roof that simply wore out, and many now pay actual cash value rather than full replacement cost on older roofs. Photograph damage promptly and file before repairs begin.
Is roof replacement tax deductible? For your own home, generally no, though it adds to your cost basis when you sell. For a rental property, a full replacement is typically a capital improvement to depreciate, not a same-year deduction. Tax rules change and vary by country, so treat this as a starting point and confirm with a tax professional.
How accurate is this roof calculator? The math is exact and hand-verified, and the installed rates reflect typical 2026 national averages for the US market, but real bids move with local labor rates, permits, decking condition, stories and access. Treat the result as a budgeting estimate and a bid-checking tool, not a quote: if a contractor's number lands within 15 to 20% of this estimate, it is in the normal range; if it is far off in either direction, ask them to explain the difference line by line. Results here are estimates for planning, not professional advice.
For a typical single-family home, a full roof replacement usually falls between 8,000 and 25,000, with asphalt shingle jobs clustering near the lower end and metal or tile jobs near the top. A 1500 square foot house with a simple asphalt roof typically runs 9,000 to 13,000 including tear-off. The three drivers are roof surface area, material and local labor. Enter your numbers above for a tailored estimate.
A 2000 sq ft house often has a roof surface of 2300 to 2600 sq ft after slope and overhangs. With asphalt shingles at 4.50 installed, 10% waste and tear-off, the estimate lands near 13,000 to 15,000. Switch to metal at 11.00 and the same roof runs roughly 28,000 to 33,000 before local adjustments.
Installed cost per square foot typically runs 4.50 for asphalt shingles, 7.00 for flat or EPDM, 9.00 for wood shake, 11.00 for metal and 13.00 for clay or concrete tile. Tear-off adds about 1.25 per square foot of roof area on top. Steep pitches and complex roofs push the effective rate higher because of the pitch multiplier and extra labor.
One roofing square equals 100 square feet of roof surface. Roofers price materials and labor by the square, so a 22-square roof is 2200 sq ft of covered surface. This calculator also shows your cost per square so you can compare it directly with contractor bids.
Yes. A steeper roof has more surface area than a flat one with the same footprint, and crews charge more for steep work because of staging, safety and slower installation. This calculator applies multipliers from 1.00 for flat roofs up to 1.41 for very steep 12:12 roofs.
About 1.25 per square foot of roof area, so 2250 on an 1800 sq ft roof. Tear-off covers removing the old roofing, disposal fees and exposing the decking for inspection. Skipping it with an overlay saves the money but hides decking damage, which can cost far more when discovered later.
Home square footage measures living space on the floor plan. Roof area measures the actual sloped surface, which is always larger because of pitch, eaves and overhangs. Pricing from the floor plan underestimates the job, which is why this calculator asks for roof area and applies a pitch multiplier.
Installed metal roofing runs about 11.00 per square foot, roughly two to three times asphalt. It is worth it when you value lifespan: 40 to 70 years versus 20 to 30 for asphalt, plus better snow shedding and heat reflection. Over a long stay, one metal roof can cost less than two asphalt replacements.
Asphalt shingles last 20 to 30 years, architectural shingles 25 to 35, wood shake 20 to 40, flat EPDM 20 to 30, metal 40 to 70 and clay or concrete tile 50 years or more. Ventilation, climate and installation quality move these ranges up or down.
Usually yes, for one layer, where local code allows it. An overlay saves the tear-off cost but adds weight, can void or shorten warranties and hides damaged decking. Two existing layers always require a full tear-off before new roofing goes on.
It covers sudden accidental damage such as hail, wind or fallen trees, not wear and tear or age. Many policies pay actual cash value on older roofs rather than full replacement cost. Document damage with photos and file the claim before starting repairs.
Late winter and early spring are typically the slowest season for roofers in most climates, which can mean keener pricing and faster scheduling. Avoid peak storm season if you can, and never let a contractor rush a job into bad weather just to hit a discount deadline.
On your own home it generally is not, though it increases your cost basis when you sell. On a rental property it is usually treated as a capital improvement to depreciate rather than a same-year deduction. Confirm the current rules with a tax professional in your country.
The calculation itself is exact and every step is shown, and the rates reflect typical 2026 national averages. Local labor markets, permits, decking repairs and roof complexity move real bids around, so use the result as a budgeting estimate and a way to check contractor quotes, not as a binding price.
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