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Roof Replacement Cost Calculator

What a roof replacement costs, including tear-off.

Your measurementsEvery assumption editable01

One square is 100 sq ft of roof surface. Use the roofing calculator to work it out from footprint and pitch.

$200–400 per square is typical for asphalt. Steep or complex roofs cost more.

Zero for new construction or an overlay.

Underlayment, drip edge, starter, ridge cap, flashing and nails.

Deck repair is the classic surprise once the old roof is off.

Estimated costCalculated live02

Result

$10626–17710estimated

Midpoint $14168 — about $644 per square

Roof size
22 square
Materials
$4070
Labour49% of the subtotal
$6160
Tear-off and disposal
$2420
Subtotal
$12650
Contingency12%
$1518
Midpoint estimate
$14168
Likely range±25%, the usual concept-stage spread
$10626 – $17710
Cost per square
$644

This is a budgeting figure, not a quote. Regional labour rates vary by a factor of two or more across the country, and the same job priced in a busy season and a quiet one can differ by a third. Get three local quotes before committing to anything.

The range matters more than the midpoint. Construction estimating works to roughly ±25% until a scope is drawn and priced, and a single confident number would be pretending to a precision that does not exist at this stage.

Labour is usually the larger half and the more variable half. If the figure looks wrong, the labour rate is almost always the input to revisit first — material prices are far more consistent between regions than crews are.

Priced by the square — a hundred square feet of roof surface, not floor area. Tear-off is separate and per layer, because a roof carrying two old layers costs meaningfully more to strip than one.

Why use this tool?What it does differently03

Why use this tool?

Tear-off per layer

Two existing layers cost twice the removal of one, and it is often forgotten entirely.

Accessories included

Underlayment, drip edge, starter, ridge cap and flashing, which add up to real money.

Honest range

±25%, plus a higher default contingency because deck rot is the classic surprise.

Squares, not square feet

Roofing is quoted per hundred square feet of sloped surface. Use the roofing calculator to get there from footprint and pitch.

How this worksThe method04

How this roof replacement cost calculator works

Everything is priced per square — one hundred square feet of actual roof surface. That is not the same as your building footprint: a 6/12 roof is about twelve per cent larger than the plan beneath it, and a 12/12 over forty per cent larger.

Material, underlayment and accessories, labour and tear-off are each rated per square and summed. Tear-off multiplies by the number of existing layers, since each one has to come off and go in the skip.

The contingency defaults higher here than elsewhere because roof decking damage is only discovered once the old covering is off, and replacing sheathing mid-job is both common and unbudgeted.

How to use itStep by step05

How to use it

  1. Step 1: Work out your roof size

    In squares. The roofing calculator converts footprint and pitch into that figure.

  2. Step 2: Pick a material

    Asphalt through slate. The spread between them is very large.

  3. Step 3: Count existing layers

    Zero for new construction. Two layers means double the tear-off.

  4. Step 4: Budget for deck repair

    Keep the contingency. Rotten sheathing is discovered, not predicted.

Example usageWorked figures06

Example usage

A typical asphalt reroof
22 squares of architectural shingle with one layer to strip: $4,070 material and accessories, $6,160 labour, $2,420 tear-off — about $14,168 midpoint, ranging $10,626 to $17,710. Roughly $644 per square.
Metal instead
Raising the material rate to $350 per square takes the midpoint to about $20,600. Metal lasts far longer, which is the argument for it.
New construction
Setting tear-off layers to zero removes $2,420 and drops the midpoint to about $11,458.
Frequently asked questionsCommon questions07

Frequently asked questions

How much does a new roof cost?

For a typical house, roughly $10,000 to $18,000 for architectural asphalt including tear-off. Metal, tile and slate cost substantially more, and complex roofs with many valleys add labour.

What is a roofing square?

One hundred square feet of roof surface. Roofing is quoted in squares rather than square feet, and it is sloped area rather than building footprint.

Does tear-off cost much?

Around $100 to $150 per square per layer, including disposal. A roof carrying two old layers effectively doubles that line.

Can I roof over the existing shingles?

Sometimes, depending on local code, how many layers are already there, and the condition of the deck. It saves tear-off but adds weight and usually shortens the new roof's life.

Why keep a high contingency?

Because rotten decking is only visible once the old roof is off. It is the single most common cost overrun on a reroof.

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