Enter your roof size and material, and get a low-to-high replacement cost estimate broken into materials, labor and tear-off. Every rate behind it is published on our roof replacement cost guide, and the arithmetic is shown next to the result. Updates as you type. No signup.
Actual roof surface, not the floor area of the house.
One square is 100 sq ft of roof surface.
$300 to $600 per square installed.
Removal costs $100 to $300 per square.
Two layers is twice the material to strip and haul away.
Assumes 10 to 20 percent of the deck needs replacing at $200 to $500 per square. Sensible on an older roof, since decking is only visible once the old roof is off.
18 sq × ($300 to $600) + tear-off
1,800 ÷ 100 = 18
total ÷ squares
18 × ($100 to $250)
18 × ($200 to $350)
The materials and labor split is published for asphalt shingles only. Our source gives one combined installed price for every other material, so for those we show the total and say so rather than inventing a split.
Don’t know your roof area? Measure your pitch with the roof pitch calculator, then turn your footprint into true surface area with the roof area calculator.
This is an estimate, not a quote. It applies published national rates to the size you typed in. It cannot see your roof, your region, or what is under the old shingles. Get at least three written estimates and use this to check them. The methodology page lists every source and rounding rule.
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How this calculator works
There is no hidden pricing engine. The calculator multiplies your square count by published national rates and adds the two costs most often left out of a quote. Every rate below appears on the roof replacement cost guide with its source.
| Component | Rate used | When it applies |
|---|---|---|
| Asphalt shingles, installed | $300 to $600 per square | Always, if selected |
| Flat / low-slope membrane | $300 to $1,100 per square | Always, if selected |
| Metal | $500 to $1,600 per square | Always, if selected |
| Wood shakes | $700 to $1,500 per square | Always, if selected |
| Tile | $700 to $2,500 per square | Always, if selected |
| Slate | $1,000 to $3,000 per square | Always, if selected |
| Tear-off and disposal | $100 to $300 per square, per layer | If you remove the old roof |
| Decking contingency | 10 to 20 percent of squares at $200 to $500 | Only if you tick the box |
Totals are rounded to the nearest $100 and per-square figures to the nearest $5, the rounding rules used across this site.
Two checks that the model is not made up
The materials and labor split adds up exactly. Our source publishes asphalt materials at $100 to $250 per square and labor at $200 to $350. Add them and you get $300 to $600, precisely the installed range it publishes separately. We did not reconcile those figures; they already agree.
The all-in figure lands on the published one. Choose asphalt, tear-off, one layer, and the result is $400 to $900 per square all in, whatever size you enter. That is exactly the all-in range our source publishes for a shingle replacement including removal.
What each input changes
Roof size
The input that moves the number most, and the one people get wrong most often. Roof surface area is not house footprint. A 2,000 square foot house with a typical 6:12 roof has about 2,235 square feet of roof, and a steeper roof has more. Two bids on the same house often differ for no reason other than that one estimator assumed the wrong slope, so it is worth settling your own figure first. If you do not have that number, work it out with the roof area calculator or convert an area into squares with the roofing square calculator.
Material
Material sets the per-square rate, and the gap from cheapest to dearest is a factor of ten. Asphalt at $300 to $600 is why the national averages sit where they do, and it is what the large majority of American replacements use. Slate also needs structural work on many houses before it is even possible, which this calculator does not price. For the detail behind these rates, see the shingle, metal and flat roof guides.
Tear-off and layers
Removing the old roof costs $100 to $300 per square, and two layers means twice as much to strip and haul, so the calculator doubles that line. This is the most common reason two quotes on the same house differ: one includes full tear-off to bare sheathing, the other is an overlay. Ask which you are being quoted before you compare two prices, because they are not the same job. An overlay is cheaper now and dearer later, since the next replacement has two layers to strip.
Decking contingency
Decking is the sheathing under the underlayment, and nobody can see its condition until the old roof is off. Replacing it runs $200 to $500 per square of affected area. The checkbox allows for 10 percent of the roof at the low end and 20 percent at the high end. On a roof over about twenty years old, or one that has been leaking, tick it. A quote that does not mention decking is a quote with an open end on it, so ask for the rate in writing before work starts.
What this calculator deliberately does not do
No pitch or complexity multiplier. A steeper, cut-up roof does cost more, but no source we cite gives a per-square price multiplier for it. What pitch changes is your area, and that is handled upstream by the roof pitch calculator and the roof area calculator. Complexity also raises the waste allowance, typically 10 to 15 percent, which the roofing square calculator lets you set. We let those tools change the input rather than invent a price factor.
No state adjustment. Labor rates and disposal fees vary widely, and the states our source covers span roughly $5,400 to $17,900. We publish no per-state figures anywhere on this site, so there is no defensible multiplier to put here.
No materials and labor split outside asphalt. Our source breaks the price into components for asphalt only. Splitting the others using the asphalt ratio would look more useful and be less true, so those boxes stay empty and say why.
None of this replaces the roof replacement cost guide, which explains where each rate comes from and what moves a real quote. The calculator is the short version: it applies those rates to your roof instead of to an average one.
How to use the result
- Treat the range as the band a reasonable quote should sit in, not as a price.
- Compare it against the per-square figure in each written estimate, since that is what is genuinely comparable between bids.
- Ask every contractor for the square count they measured. A big difference from yours means one of you has the area wrong.
- Ask whether the price includes full tear-off to bare sheathing, and the rate for replacing bad decking.
- Treat a bid well under the low end as a question rather than a bargain. It usually means a smaller scope.
A cut-up roof, a difficult site, a high-cost metro or a premium product can all push a legitimate price above a national band. The number is here to make you ask why, not to tell you what to pay.
Sources used on this page
- HomeGuide roof replacement cost guide, dated November 7, 2025. Installed cost per square by material, the materials, labor and removal breakdown, decking replacement cost and state ranges.
Every rate in this calculator is published on our roof replacement cost guide, which lists its sources in full. The methodology page explains how sources are used across the site, the rounding rules, and how often figures are reviewed.
Related calculators and guides
- Roof Pitch Calculator: find your pitch, angle and surface area multiplier.
- Roof Area Calculator: turn footprint, pitch and overhang into true roof surface area.
- Roofing Square Calculator: convert area into squares, waste and shingle bundles.
- Roof Replacement Cost: every rate used here, with its source and the full breakdown.
- Roof Repair Cost: if you are not sure you need a replacement at all.
Roof replacement cost calculator FAQ
How much does it cost to replace a roof?
An asphalt shingle replacement runs $300 to $600 per roofing square installed, or $400 to $900 per square once tear-off and disposal are included. On an 18 square roof that is $7,200 to $16,200. Enter your own roof size above for a figure that matches your house rather than an average one.
What is a roofing square?
One square is 100 square feet of roof surface. Contractors quote in squares, so a price of $450 per square on an 18 square roof is an $8,100 job. That is why this calculator shows a per-square figure alongside the total: it is the number you can genuinely compare between bids.
Do I enter my house size or my roof size?
Your roof size. A roof is larger than the house under it because it slopes. A 2,000 square foot house with a typical 6:12 roof has about 2,235 square feet of roof. Use the roof area calculator to work yours out from your footprint, pitch and overhang.
Does this calculator include tearing off the old roof?
Yes, if you leave the tear-off option set to yes. Removal costs $100 to $300 per square, and a roof with two existing layers has twice as much to strip, so the calculator doubles that line. Turn it off for an overlay or new construction.
Why does the calculator not ask for my state?
Because we have no state-level figures we can defend. Labor rates and disposal fees vary widely, and the states our source covers span roughly $5,400 to $17,900, but we do not publish per-state numbers anywhere on this site rather than derive figures we cannot check. Treat the result as a national band and expect a high-cost metro area to sit above it.
Why is there no materials and labor split for metal or slate?
Our source publishes that breakdown for asphalt shingles only, at $100 to $250 per square for materials and $200 to $350 for labor. For every other material it gives one combined installed price. Splitting those with the asphalt ratio would look more helpful and be less accurate, so those boxes stay empty.
Should I add the decking contingency?
Tick it if the roof is over about twenty years old or has been leaking. Decking is only visible once the old roof is off, and replacing it costs $200 to $500 per square of affected area. The box adds an allowance for 10 to 20 percent of the roof, which is a planning assumption rather than a prediction.
Is this a quote?
No. It applies published national rates to the roof size you typed in, and it cannot see your roof, your region or what is under the old shingles. Use it to check the written estimates you get, and get at least three of them.