What does it cost to replace a roof?
Type your home’s square footage — get an itemised cost range in seconds. Nothing is sent anywhere.
Your home
The number from your listing or tax record. Not the roof — the tool works the roof out.
Your estimate
Roof replacement cost
Most likely
—Enter your home size to see a range
One number is all it takes. Nothing is sent anywhere.
- Your roof
- —
- Squares
- —
- Per square
- —
Enter your home size to begin.
Your roof
Labour rates drive most of the regional difference.
Advanced Known roof size, decking, skylights, permits
If a roofer measured it, enter it here and the tool stops estimating the size.
Check a quote you’ve been given See whether a contractor’s price fits your roof
Stays in this browser, like everything else here.
Enter a quote above and it is compared against your estimate.
Where the money goes Every line item, with its source
| Line item | Low | Most likely | High |
|---|---|---|---|
| Total | — | — | — |
Your breakdown appears once you enter a home size.
Compare materials on your roof Total cost and cost per year of life
| Material | Most likely | Life | Per year |
|---|
Cost per year divides the estimate by the midpoint of the material’s expected life. It ignores maintenance, repairs, and the fact that you may move before the roof wears out.
Enter a home size to compare materials.
What would move this number The factors worth pinning down before you sign
Enter a home size to see what matters most.
Method, sources, and limits How the number is built and what it cannot know
Working out your roof
footprint = living area ÷ stories
roof area = footprint × pitch factor × area factor
The pitch factor is arithmetic, not opinion: √(rise² + 144) ÷ 12. A 6/12 roof is 1.118×
larger than its footprint; a 12/12 roof is 1.414× larger. The area factor (1.07–1.18) covers the eave
overhang and the extra planes a cut-up roof carries — real surface a roofer measures, not offcuts. The
material you buy and throw away when cutting is already inside the published per-square prices, so it is
not counted twice.
This is the single biggest reason published numbers disagree. A “2,000 sq ft roof” and a “2,000 sq ft house” are not the same thing. A 2,000 sq ft single-story home has roughly 2,400 sq ft of roof. The same home over two floors has roughly 1,200.
Building the cost
Every line item is priced as a low–high band from published 2026 cost data. “Most likely” is the midpoint of that band — a convenience, not a separate measurement. Labour premiums for steep pitch and multi-story access apply to the labour share only, taken as 55% of installed cost.
Why published averages disagree by more than double
Cost guides report a US average near $12,000 for an asphalt replacement. The Remodeling Cost vs. Value report puts the same job at $31,871 — because it prices a specified 30-square hip roof with two skylights, synthetic underlayment, drip edge, and aluminium flashing. Neither is wrong. They describe different jobs. That is why this tool gives you a range and shows you the line items rather than a single confident number.
Why this differs from the "$12,000 average" you have read
Cost guides report a US average near $12,000 ($8,000–$16,000). They describe roughly a 2,000 sq ft roof — about 20 squares — on a plain scope, not a 2,000 sq ft house. A 2,000 sq ft single-storey house carries about 24 squares of roof, and this tool's default also includes a decking allowance and a permit. Same trade, different job.
Regional adjustment
States with a directly published cost figure are marked measured. Every other state is assigned to the nearest cost tier from published construction-wage patterns and is marked grouped. The interface tells you which one you are getting. A grouped state is a regional adjustment, not local pricing.
What this tool cannot know
- The condition of your decking. It is only visible once the old roof is off.
- Your local permit office’s fee schedule.
- Storm-driven price surges, which can move a whole metro for a season.
- Your contractor’s overhead, warranty, crew, and how busy they are this month.
- Anything about your actual roof. Nobody has measured it.
This is a budgeting estimate, not a quote. Use it to size up the job and to ask better questions. Only a roofer on your roof can price it.