To estimate roof replacement cost, find your roof area in squares (footprint × pitch factor ÷ 100), multiply by your installed price per square, then add tear-off per layer, any steep-roof surcharge, the dumpster and the permit. For a national benchmark, the Remodeling 2025 Cost vs. Value Report (www.costvsvalue.com) puts the average asphalt shingle replacement at $31,871 for a 30-square roof, about $1,062 per square, and a 3,000 ft² standing-seam metal roof at $51,865, about $1,729 per square.
This roofing cost calculator is for homeowners comparing bids, landlords budgeting a reroof and anyone who has a price per square and wants a total. It measures the roof from the footprint and pitch (or takes the area or squares from a measurement report) and keeps every price editable. Nothing is pre-filled as a market price, because your local quote is the only number that matters.
How to use the roof replacement cost calculator
- Choose how you know the roof size: house footprint and pitch, roof surface area, or squares.
- Pick the material. The calculator works the same for each; the label reminds you which price to enter.
- Enter the installed price per square from your quote. If the quote is per square foot, multiply by 100.
- Enter how many existing layers come off and the tear-off price per layer, if the quote lists it separately.
- Add a surcharge percentage for steep or complex roofs only if your roofer charges one, plus the dumpster, permit and extras such as replacement decking or skylight flashing.
- Read the total, the all-in price per square and per square foot, and the cost breakdown.
National average roof replacement cost (2025)
The Cost vs. Value Report is the most widely cited public benchmark for remodeling costs. For 2025 it estimated costs for 28 projects, building a national baseline from Bureau of Labor Statistics CPI and PPI data and BEA price indexes, with local building costs from Verisk's XactRemodel estimating software. Its asphalt roofing project is defined as: remove existing roofing to bare wood sheathing; install 30 squares of minimum 235-lb fiberglass asphalt shingles with new 30-lb felt or equivalent synthetic underlayment, galvanized drip edge and aluminum flashing; rectangular hip roof with custom flashing at two skylights and a vented ridge. The national average job cost is $31,871, or $1,062 per square ($10.62 per ft²) once divided by the 30 squares.
The metal project removes the old roof, adds an ice-barrier membrane at the perimeter and premium synthetic underlayment, and installs 3,000 ft² of prefinished standing-seam metal with matching drip edge, gable trim and vented ridge, again with two skylights. Its national average is $51,865: $1,729 per square or $17.29 per ft². On resale, Realtors surveyed for the report estimated that the asphalt job recoups 68% of its cost and the metal job 50%.
Two cautions. These per-square figures include the skylight and ridge work, so a plain roof will usually price lower per square and a cut-up roof higher. And the report publishes regional and city figures that can differ a lot from the national number; check the regional data at costvsvalue.com before treating the national average as your budget. © 2025 Zonda Media, a Delaware Corporation. Complete data from the Remodeling 2025 Cost vs. Value Report can be downloaded free at www.costvsvalue.com.
How the estimate is calculated
- Roof area = (length + 2 × overhang) × (width + 2 × overhang) × √(rise² + 144) ÷ 12. Hip and gable roofs of the same pitch give the same area; see the roof pitch calculator for the factor.
- Squares = roof area ÷ 100.
- Roofing = squares × your installed price per square.
- Tear-off = squares × layers × tear-off price per layer.
- Surcharge = (roofing + tear-off) × surcharge %.
- Total = roofing + tear-off + surcharge + dumpster + permit + other.
Contractors price on the roof area they measure, sometimes with their own waste factor built into the price per square. If your quote lists squares, compare its count with the calculator's. A big gap is worth asking about. For material counts (bundles, starter, ridge cap and underlayment), use the roofing shingles calculator.
Worked example: comparing a quote
A 50 × 30 ft house with 1 ft overhangs and a 6/12 roof has 52 × 32 = 1,664 ft² of footprint × 1.118 = 1,860 ft², or 18.6 squares. Suppose a quote reads (illustrative numbers, not market data) $450 per square installed, $60 per square to tear off one layer, a $550 dumpster, a $300 permit and $400 for decking repairs. Roofing is $8,372, tear-off $1,116, and the total is $10,738: $577 per square or $5.77 per ft² all-in.
Same roof with two layers to remove and a 15% steep/complex surcharge: tear-off doubles to $2,232, the surcharge adds $1,591, and the total becomes $13,445. Note too that IRC R908.4 does not allow a third layer over two existing ones, so a two-layer roof must be stripped.
Roof squares by house size and pitch
Squares of roof (1 ft overhang all round, no waste). Multiply by your price per square for the roofing line of your estimate.
| House footprint | 4/12 | 6/12 | 8/12 | 10/12 | 12/12 |
|---|---|---|---|---|---|
| 40 × 25 ft (1,000 ft²) | 12 sq | 12.7 sq | 13.6 sq | 14.8 sq | 16 sq |
| 50 × 30 ft (1,500 ft²) | 17.5 sq | 18.6 sq | 20 sq | 21.7 sq | 23.5 sq |
| 60 × 30 ft (1,800 ft²) | 20.9 sq | 22.2 sq | 23.8 sq | 25.8 sq | 28.1 sq |
| 60 × 40 ft (2,400 ft²) | 27.4 sq | 29.1 sq | 31.3 sq | 33.9 sq | 36.8 sq |
| 70 × 40 ft (2,800 ft²) | 31.9 sq | 33.8 sq | 36.3 sq | 39.4 sq | 42.8 sq |
Converting price per square, per square foot and total
Every $100 of price per square adds $1.00 per ft² of roof, and adds squares × $100 to the total. Use this to translate between the ways quotes are written:
| Roof size | Squares | Each $100/sq adds | Each $1/ft² adds |
|---|---|---|---|
| 1,200 ft² | 12 | $1,200 | $1,200 |
| 1,500 ft² | 15 | $1,500 | $1,500 |
| 1,800 ft² | 18 | $1,800 | $1,800 |
| 2,000 ft² | 20 | $2,000 | $2,000 |
| 2,400 ft² | 24 | $2,400 | $2,400 |
| 3,000 ft² | 30 | $3,000 | $3,000 |
| 3,500 ft² | 35 | $3,500 | $3,500 |
What changes the price
- Material. In the 2025 report, metal costs about 1.63 times as much as asphalt for the same 3,000 ft² roof.
- Tear-off layers. Under IRC R908.3 a replacement goes down to the deck, and every extra layer means more labor and disposal weight.
- Pitch and height. Steeper roofs have more area and need fall protection and slower work.
- Complexity. Valleys, dormers, skylights, chimneys and walls each need flashing and cutting.
- Decking. Rotted sheathing found during tear-off is usually priced per sheet on top of the contract.
- Low slopes. Shingles are only allowed down to 2:12, with double underlayment up to 4:12 (IRC R905.2.2); flatter sections need a different, often pricier, system.
Common mistakes
- Pricing by floor area. A two-story house has half the roof of a ranch with the same living space; a steep roof has more than its footprint.
- Comparing per-square prices that include different things. Check whether tear-off, dumpster, permit, underlayment upgrades and ridge vent are included.
- Treating a national average as a quote. The Cost vs. Value numbers describe one defined job. Your roof, region and season will differ.
- Forgetting the resale angle. A new roof recovers part of its cost at sale, but the report's recoup figures are Realtor estimates.
Related: count shingles with the roof shingle calculator, check slope and rafters with the roof pitch calculator, and budget other projects with the renovation cost calculator.
Frequently asked questions
How much does it cost to replace a roof?
According to the Remodeling 2025 Cost vs. Value Report (www.costvsvalue.com), the national average job cost for an asphalt shingle roof replacement is $31,871. That job is 30 squares (3,000 ft² of roof) with full tear-off, so it works out to about $1,062 per square or $10.62 per square foot, including two skylights and a vented ridge. Your price depends on your market, roof size, pitch and the number of layers removed; get local quotes.
How much does a metal roof cost compared with shingles?
In the same Cost vs. Value Report, a standing-seam metal replacement on a 3,000 ft² roof averages $51,865 nationally, about $1,729 per square or $17.29 per ft². That is 63% more than the asphalt shingle job of the same size.
What is the cost to replace a roof per square foot?
Divide the total quote by the roof surface area, not the house's floor area. The Cost vs. Value asphalt figure is about $10.62 per ft² of roof. A roof is larger than its footprint: at 6/12, each square foot of footprint is 1.118 ft² of roof, so a per-square-foot price based on the house's floor area will be wrong.
How much of a new roof's cost do you get back when selling?
The 2025 report estimates that an asphalt shingle replacement recoups 68% of its cost at resale ($21,501 of value for $31,871 spent), and a metal roof 50% ($25,972 for $51,865). Those values come from a survey of Realtors, not sales data.
How many squares is my roof?
One square is 100 ft² of roof surface. Multiply the footprint including overhangs by the slope factor and divide by 100. A 50 × 30 ft house with 1 ft overhangs at 6/12 has 1,860 ft², or 18.6 squares.
Do I have to tear off the old roof?
Under IRC R908.3, a roof replacement removes existing layers down to the deck. A recover (new shingles over old) is only allowed in limited cases under R908.4, and never where the roof already has two or more layers or the old roof is water-soaked or deteriorated. Each layer removed adds labor and disposal, so the calculator multiplies your tear-off price by the number of layers.
Does roof pitch change the cost?
Yes, in two ways. A steeper roof has more surface for the same footprint (8/12 is 20% more than flat, 12/12 is 41% more), which the calculator handles through the slope factor. Many roofers also add a steep-roof charge for safety equipment and slower work; enter it as a surcharge if your quote has one.
Why doesn't the calculator fill in a price?
Published national averages are useful for a sanity check, but the Cost vs. Value Report's terms do not allow its data to be built into calculators, and local prices vary widely. Enter the per-square price from your quote and the calculator scales it to your roof, tear-off layers and extras.
What does the Cost vs. Value roofing job include?
The asphalt job removes the old roofing to bare sheathing and installs 30 squares of minimum 235-lb fiberglass asphalt shingles (minimum 25-year warranty) on new 30-lb felt or synthetic underlayment, with galvanized drip edge, aluminum flashing, custom flashing at two skylights and a vented ridge cap, on a rectangular hip roof.
Sources & method
- Remodeling 2025 Cost vs. Value Report (www.costvsvalue.com) — 2025 national averages for 28 projects
- Cost vs. Value — Roofing Replacement | Asphalt Shingles: project description (30 squares, tear-off, hip roof, two skylights)
- Cost vs. Value — Roofing Replacement | Metal: project description (3,000 ft² standing seam, tear-off)
- Cost vs. Value 2025 — Methodology (BLS CPI/PPI and BEA indexes, Verisk XactRemodel local costs, Realtor survey for value)
- ICC, 2024 International Residential Code, Chapter 9 — R908.3 roof replacement (remove to the deck), R908.4 roof recover (not over two or more existing layers), R905.2.2 shingle slope
Results are estimates for general information. Found an error? It helps everyone — see our methodology.