Free roof replacement estimator

Roof cost calculator — priced at your own numbers

Put in the squares somebody measured and the rates from the quotes in front of you, and this builds the estimate line by line: covering and labor by the square, tear-off by the square per layer, disposal by the ton, the two access charges that are about reaching the roof rather than covering it, and an allowance for the sheathing nobody can size until the shingles are off. It ships no price list of its own and works out no geometry. The contingency stays a visible line rather than a multiplier, because a padded total cannot be laid beside a real bid.

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Your rates only
Tear-off by the layer
Contingency stays visible

Squares of roofSloped surface divided by 100. This page takes that figure and does not work it out — no footprint, no pitch, no multiplier.Layers already up thereCount them at a rake edge or a vent cut-out, where the stack shows in section. Two is common on a house that has been done once before; three is a tear-off nobody quoted for.

Going over the top instead. Zeroes the tear-off, the disposal and the deck allowance, because none of the three happens on a re-cover — and takes with them the only chance to look at the sheathing.

Deck expected to need replacing (%)A number nobody can know until the roof is bare. Kept as its own line so that when the crew finds none of it, the credit is visible.Contingency (%)Sits on top of the subtotal as a line of its own rather than being folded into the rates. It is your allowance, not a researched figure.

Weight of one layer, per square (lb)210 lb to start — one layer of asphalt shingles off a square: a bundle weighs 55 to 80 lb and three make the square. It moves with product weight and how wet the load is — old shingles hold water, and a torn-off square in the rain can weigh a third more than it did dry. Weigh one bundle of what is coming off if you can get to it.

Total at the rates you entered

$0.00

Subtotal: $0.00
Contingency, 10%: $0.00
Per square foot of roof: $0.00

Nothing is priced yet. Fill in the rates from the bids in front of you and the lines build up here — a row left blank is left out rather than guessed at.

What comes off before anything goes on

Old covering to shift: 2.52 tons
Square-layers to strip: 24
Dumpster loads: 2
Deck sheets allowed for: 8

Tear-off is priced per square per layer, which is the line most quotes get compared wrongly on: a second layer roughly doubles both the labor and the tonnage, and a roofer who bid one layer after looking at the eave from the ground will come back for the difference. 2.52 tons will not fit one small container — the weight allowance included in the base price of a small construction dumpster before overage is charged, so this is 2 of them or one larger one.

Your rates, from your own quotes

Quantities above are worked out from the squares and the layers; every dollar below is yours. There is no default price on this page, in either direction.

Per square of roof

Roof coveringShingles, panels or tile — whatever the quote calls the field materialUnderlayment and ice barrierDrip edge, starter, cap and flashingInstallation laborSteep-slope chargeCharged above about 7:12, where the crew stops walking the roof and starts staging itSecond-storey or hard-access chargeLadder distance, a conveyor instead of a driveway, or a roof a truck cannot park under

Removal, disposal and the deck

Tear-offPer square, per layer — not per square of roofDisposalThe tipping fee your hauler charges by weightContainer drop and haulSheathing replacedSheet and labor together — a 4 by 8 sheet of roof sheathing

Counted once, not by area

Permit
Pipe boots and vent flashings
Skylight flashing kits
Chimney or wall step flashing
Gutter and downpipe replacement

One arithmetic note worth keeping: the two access charges are entered per square because that is how they land on a quote, but neither is really about area. A steep roof and a reachable one cost the same to cover and different amounts to stand on, so if a bid raises the material rate rather than adding an access line, the two bids in front of you are not measuring the same thing. Compare them at the per-square figure and ask what is inside it.

How to cost a roof replacement

Squares in, layers counted, and two allowances kept where you can see them.

Start from squares somebody has already measured
This page takes the roof as a number and never works one out, which keeps the money separate from the geometry. Twenty-four squares means 2,400 square feet of sloped surface. If all you have is a bid, divide its total by the squares written on it and you have the all-in rate to compare against; if you have neither, measure the roof first and come back, because a cost estimate built on a guessed area is a guess wearing a decimal point.
Count the layers before you price a single line of removal
Look at a rake edge, a vent cut-out or the step where the roof meets a wall — the stack shows in section wherever the covering is cut. Tear-off is charged per square per layer and disposal is charged by weight, so a second layer roughly doubles both. This is the item that most often turns a firm quote into a variation, because a roofer who counted from the driveway saw one layer and the crew found two on the Monday.
Keep the deck allowance and the contingency as their own lines
Nobody can tell you how much sheathing is soft until the roof is bare, so set a percentage you can live with and let it sit on the estimate as a countable number of sheets. When the crew finds none of it, the credit is obvious; when they find twice as much, the argument is about quantity rather than about whether it was included. The same goes for the contingency: folded into a rate it makes every comparison meaningless, and on its own line it is a decision anyone can see and change.

Technical specifications

Roof input	Squares, typed. No footprint, no pitch and no multiplier — this page prices, it does not measure
Tear-off	Charged per square per layer, from zero to four layers, with a re-cover switch that zeroes removal outright
Disposal	210 lb a square per layer by default, converted to short tons and editable to what is actually coming off
Container	A 2 ton weight allowance per drop, so the load count follows the tonnage rather than the roof size
Deck allowance	A percentage you set, turned into 4 × 8 sheets of 32 ft² and priced per sheet including labor
Access charges	Two separate per-square lines — steep-slope and second-storey — both entered by you
Contingency	Applied to the subtotal as its own visible line, never rolled into a rate
Prices supplied	None. Every rate on this page is one you typed, and nothing is uploaded or kept

Frequently asked questions

Why are there no prices already filled in?

Because a published roofing rate is wrong for most of the people reading it on the day it is published. Labor is the majority of a re-roof and it tracks local wages, local licensing and how busy the market is after the last storm; the same twenty-four square roof is two very different invoices four hundred miles apart. Every field on this page starts empty on purpose, and the numbers you should put in them are the ones on the quotes in front of you or the ticket from your supplier.

How do I find out how many layers are already on my roof?

Lift the drip edge at a rake or look into a vent penetration, where the covering has been cut and the stack is visible in section. From the ground, a roof carrying two layers usually sits noticeably proud at the rake board and the shingle line looks thick against the fascia. It matters beyond the price: the IRC caps a re-cover at two layers total, so a roof already carrying two has no option but a full strip whatever the bid says.

How much of a roof bill is removal rather than new material?

Commonly a fifth to a third once tear-off, disposal and the container are added together, and the panel here reports the share so you can see it for your own numbers. It is the part of the invoice that buys nothing visible, which is why it is the first thing an underquoted bid leaves thin. Weight is the driver: a square of asphalt is around 210 lb a layer, so a twenty-four square roof with two layers is more than five tons to lift, carry down and pay a tipping fee on.

What happens if the crew finds rotten sheathing?

It is replaced by the sheet, priced at a rate that should already be in the contract before anyone climbs a ladder. Ask for the per-sheet figure in writing at quoting time, including the labor, because a rate agreed while the roof is open is never the rate you would have negotiated while it was closed. Rot clusters where water sat: valleys, the eave inside the ice line, around a chimney and under a failed vent flashing, so a roof that has leaked in one of those places will need more than a token allowance.

Is going over the old roof actually cheaper?

It is cheaper on the day and it removes the only chance anyone gets to look at the deck. A re-cover skips the tear-off labor, the tonnage and the tipping fee, which is real money — but it also buries whatever is happening underneath, adds weight to the structure, and makes the next roof a two-layer strip at the higher rate. Ticking the re-cover box here zeroes those three lines so the saving is visible, which is the point at which most people decide what they are actually buying.

Two quotes are thousands apart. How do I compare them?

Reduce both to a rate per square and then ask what is inside each one. Almost every large gap comes from one of four things: a different layer count, ice barrier included in one scope and absent from the other, a deck allowance that is real in one bid and imaginary in the second, or a steep or access charge that one estimator built into the material rate instead of naming. Run both through the same fields here and the difference usually stops being a mystery within ten minutes.

Does a steeper roof cost more per square to cover?

More to work on, not more to cover — the material is identical and the surface is already counted. What changes is that above roughly 7:12 a crew stops walking the roof and starts staging it, which slows every trip and adds equipment, and a second storey adds ladder distance to every one of those trips. This page keeps both as separate per-square lines you enter yourself, because a bid that hides an access charge inside the shingle rate cannot be compared with one that names it.

About what actually moves the price of a roof

A re-roof is priced on four things and the covering is only one of them. The second is removal, which buys nothing you can point at and routinely runs a fifth to a third of the invoice. The third is access — how a crew gets material up, moves along the roof and gets waste down — which is why a steep second-storey roof and a walkable single-storey one at the same square footage are not the same job at all. The fourth is the deck, which is unknown by definition on the day the quote is written. Any estimate that hands you a single number per square has made a decision about all four on your behalf, and the whole purpose of splitting them here is that you can see which decision each bidder made.

Tear-off is where quotes drift furthest from each other, and it is almost always the layer count. Charging is per square per layer, so a second layer roughly doubles the labor and the tonnage at once — and the weight is not small. At around 210 lb per square per layer, a 24 square roof with two layers is just over five tons that has to be lifted off, carried down a ladder and paid for at a transfer station by the ton. This is also the reason containers are counted by weight allowance rather than by container size: a small box filled with shingles hits its tonnage long before it fills up.

The sheathing allowance is the honest version of the industry’s least honest line. Nobody knows what is under the old roof, and a bidder who quotes zero for deck replacement has not made the risk go away, only moved it to a change order at a rate you have no leverage over. Set a percentage, price it per sheet with the labor in, and get the rate written down before the ladders go up. The quantity that feeds all of this comes from the roof area calculator and the material breakdown from the roofing calculator and the shingle calculator. For the same rates-you-supply approach on other work, the concrete cost calculator and the bathroom remodel cost calculator are built the same way.

What happens to the quotes you type in

Every number on this page is worked out by JavaScript running in the tab you are reading it in. Nothing you type — measurements, quantities, the prices your supplier quoted you — is uploaded, logged or kept, which is also why the calculators carry on working on a site with no signal.

The rates from your bids are the most commercially sensitive thing anyone enters on this site, and they are handled the same way as everything else: read by the arithmetic in this tab, never transmitted, never stored, and gone the moment the page reloads. No contractor is contacted and no quote request is generated.