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Roof Replacement Cost Calculator Ontario (2026): Shingles, Metal, Tear-Off and HST
RoofingFree Calculator
What Should a New Roof Cost? Measure the Roof, Not the House, and Price It Before the Roofer Does.
Shingles or metal, tear-off, decking, flashing, venting and HST. No email address required to see the number.
A 1,600 sq ft bungalow does not have a 1,600 sq ft roof. It has eaves, a pitch, two chimneys and a skylight somebody put in during the 1990s, and the roofer is pricing all of those. This works the roof surface out from the footprint and the pitch, prices it with Ontario installed rates by system, and writes a scope three roofers can price the same way.
Step-by-step
Roof Replacement Cost Calculator (Ontario)
1
The roof
Length times width of the outside walls, ground floor only. A 40 by 40 house is 1,600. Not the floor area of a two-storey.
Rise over 12 in. of run. Look at the gable end: a roof that rises half as fast as it runs is 6/12.
Sets the cutting waste and part of the labour.
Only used if you answered yes.
2
What goes on it
Installed rates, Ontario, checked October 2026, per square foot of sloped roof surface. Each one includes tearing off one layer of shingles, disposal, synthetic underlayment, ice and water shield at the eaves and valleys, drip edge, standard pipe flashings and nails. What they do not include is listed below the result.
$120 per 4×8 sheet installed is the usual unit price. Nobody knows until the old roof is off.
Full coverage is worth it on low slopes, north-facing cottage roofs and anywhere ice dams have happened.
3
The things that poke through it
$650 each: new step, counter and apron flashing, sealed to the masonry. A cricket on the uphill side is extra.
$450 each for the flashing kit and labour. If the skylight is 20 years old, replace it now ($1,200 to $2,500 each) and not through the new roof.
$75 each for a new boot or cap. Most houses have 2 to 5.
$12 per foot installed. A simple gable house is 40 to 50 ft of ridge. Put 0 if the roof keeps its box vents.
$12 per foot for 5 in. seamless aluminum with downspouts. Often done the same week.
$18 per foot. Over doors, walkways, decks and the gas meter. Ignored for shingle roofs.
4
Where is the house?
Used only to tell you whether this is in our direct area or a region where we would introduce one vetted roofer.
Enter a postal code to see service coverage.
BuildersOntario.com
Your Roof Budget
Illustrative Ontario estimate
| Item | Estimate |
|---|
Estimated total with HST$0
Example only, using BuildersOntario budgeting rates checked October 2026, applied to the sloped roof surface (not the house floor area, and not the material order with waste). Includes one-layer tear-off and disposal, underlayment, code-minimum ice and water shield, drip edge and standard flashings. Excludes structural repair, fascia and soffit replacement, chimney masonry, skylight replacement, a cricket behind a wide chimney, permits where a municipality asks for one, and anything found under the old roof beyond the decking allowance. A roofer’s written quotation after walking the roof is the only binding number.
Request a Real Quotation
Your estimate becomes a written scope a roofer can price without rewriting it, so three of them price the same roof. Fill in the rest and press Send. It goes straight to our inbox, and a copy comes back to you; reply to that copy with a photo of each side of the house from the street and one of the attic if you can get to it.
What this calculator does, and what it will not do!
It does the arithmetic a roofer does on your driveway, in the order they do it: footprint plus overhangs, times the pitch factor, gives the roof surface. That surface times the installed rate for the system you picked gives the base. Then the things that make a roof slow (steep, tall, cut up) and the things that poke through it (chimneys, skylights, vents), then what is under it (tear-off layers, decking), then HST, which on a $14,000 roof is $1,820 and is never in the number you have in your head.
It does not know the deck is spongy under the north valley, that the chimney needs repointing before it can be flashed, or that the last roofer put the second layer straight over cedar shakes. Those are the day-one surprises, which is why the decking allowance is there and why a good quote carries a unit price per sheet for more. The point is that when the surprise comes, you know what the rest of the roof should cost, so you can tell a real extra from a Tuesday-afternoon invention.
A rule of thumb: in Ontario in 2026, a 1,600 sq ft bungalow with a 6/12 gable roof, one chimney, architectural shingles, one layer off, lands at $13,000 to $17,000 with HST. The same house in standing seam steel is $32,000 to $39,000. A two-storey with a hip roof and dormers runs 25 to 40% more than the bungalow in either material. The roof replacement cost guide has the worked examples.
How I price it
Installed, before HST, Ontario, checked October 2026, per square foot of sloped roof surface. A “square” in roofer’s language is 100 sq ft; multiply these by 100 for the per-square number on a quote.
| Line | Rate | Notes |
|---|---|---|
| 3-tab asphalt shingles | $5.50 per sq ft | The builder-grade shingle. 20 to 25 year rating, 15 to 20 real years in Ontario. Hard to find on a quote now; most roofers quote architectural. |
| Architectural (laminated) shingles | $6.75 per sq ft | What 80% of Ontario roofs get: IKO Cambridge, BP Mystique, GAF Timberline, Owens Corning Duration, CertainTeed Landmark. 25 to 30 real years if the attic is vented. |
| Premium or Class 4 shingles | $8.50 per sq ft | Thicker, heavier, impact-rated. Worth it where hail happens and where an insurer gives a discount for Class 4; ask yours. |
| Metal panels, exposed fastener | $10.50 per sq ft | The barn and cottage roof. 26 or 29 gauge, screws through the face with rubber washers that are the roof’s weak point in year 20. Cheapest metal. |
| Interlocking metal shingles | $13.50 per sq ft | Steel or aluminum shingles that lock to each other, hidden fasteners, look like shingles or slate from the street. 50-year warranties are common. |
| Standing seam steel | $16.00 per sq ft | 24 or 26 gauge Galvalume panels with concealed clips, seams raised 1 to 2 in. The roof you buy once. Snow slides off it, which is why the snow guard line exists. |
| Flat or low-slope membrane | $12.00 per sq ft | Two-ply modified bitumen (torch-on), EPDM rubber or TPO. For anything under 2/12. Separate page: flat roof materials. |
| Tear-off, one layer, and disposal | Included | In every rate above. A second layer is +$1.00, a third or cedar underneath +$2.00. New construction takes $0.90 off. |
| Decking | $120 per 4×8 sheet | Installed, 1/2 in. plywood or 7/16 OSB. Board decks and rotten plywood are a full re-sheet at $3.25 per sq ft. See tear-off and decking. |
| Ice and water shield | Included to code; +$0.85 for full | The Ontario Building Code wants eave protection from the edge to at least 900 mm up the slope and 300 mm past the inside of the wall; good roofers also run it in valleys and around everything that pokes through. Full-deck coverage is the upgrade for low slopes and ice-dam roofs. Page: underlayment and ice and water shield. |
| Steep pitch | +12% at 8/12, +22% at 10/12 | Roof jacks, harnesses, slower everything. Labour, not material. |
| Height | +6% two storeys, +12% three | Ladders, lifts, and the bundles going up. |
| Hip and complex roofs | +4% hip, +8% complex, plus waste | Every valley and hip is a line of cuts. Waste is 10% gable, 12% hip, 15% cut-up; it is in the material order, not the installed rate. |
| Chimney flashing | $650 each | New step, counter and apron flashing let into the mortar joints. A cricket (saddle) behind a chimney over 30 in. wide is another $400 to $700 and the code asks for it. |
| Skylight flashing | $450 each | Flashing kit and labour. A skylight older than 20 years gets replaced now, not through the new roof later. |
| Vent boots and caps | $75 each | Every plumbing stack and roof vent gets a new one. Reusing old boots is where the first leak comes from. |
| Ridge vent | $12 per foot | With the ridge cap. Only works if there is soffit intake to feed it; the $600 line opens the soffits if there is not. |
| Eavestroughs | $12 per foot | 5 in. seamless aluminum with downspouts, same week. 6 in. and leaf guards are more. |
| Snow guards | $18 per foot | Metal roofs, over anything you do not want buried in March. |
| Minimum job | $3,500 | Nobody sets up for less. Small roofs and garages pay the minimum. |
Where homeowners go wrong
- Pricing the floor area. A 2,000 sq ft two-storey has a 1,000 sq ft footprint and about 1,250 sq ft of roof. A 2,000 sq ft bungalow has 2,400. The house with less floor has twice the roof. Measure the roof.
- Comparing a quote that includes tear-off to one that does not. Same shingle, $3,000 apart, and the cheap one says “disposal extra” in 9-point type. The quote checklist is the list of what has to be on the paper.
- Not asking for the decking unit price. The roof comes off, the deck is soft, and the number is whatever the roofer says standing on your lawn. Get “$120 per sheet beyond the first two” in writing before.
- Reusing the flashing. The shingles are new, the 25-year-old chimney flashing is not, and that is where it leaks in year three. New flashing on everything, on the quote.
- Venting the roof and not the attic. A ridge vent with blocked soffits is a decoration. Ice dams come from a warm attic, not from a bad roof; the ice dam page explains why the fix is usually below the shingles.
- Signing on the driveway. The “today only” price, the 50% deposit, the one-page quote. Three quotes on this scope, 10 to 15% down, and a contract with the fourteen things in it.
What a roofer needs from you
The quotation request above hands them a written scope: the footprint, pitch, shape and height, the roof area as you calculated it (they will measure, and should), the system, what is on the roof now, the decking allowance and a unit price for more, where the ice and water shield goes, every flashing and vent as a count, the ventilation plan, and the paperwork you expect with the quote. With photos of each side of the house, a roofer can give you a firm number from a satellite measure and a site visit, and three of them will be pricing the same roof, which is the whole trick. The quote checklist and the hiring guide take it from there.
If you are in Simcoe County, Muskoka or the Georgian Bay area, the request comes to us and goes to a roofer we have used on houses we built. Everywhere else in Ontario, with your permission, we pass it to one roofer we have checked, never a list of five. If we have nobody we trust in your area yet, we will say so.
Questions people ask
How much does it cost to replace a roof in Ontario in 2026?
$5.50 to $8.50 per square foot of roof installed for asphalt shingles, $10.50 to $16 for metal, before HST. A typical 1,600 sq ft bungalow is $13,000 to $17,000 in architectural shingles with HST; a two-storey with a complex roof is $18,000 to $25,000; the same roofs in standing seam steel are a little more than double.
How do I calculate my roof area?
Footprint of the house including the garage, plus about 8% for overhangs, times the pitch factor (1.118 for 6/12, 1.202 for 8/12, 1.414 for 12/12). That is the sloped area. Divide by 100 for squares. Add 10 to 15% for the material order, not for the installed price.
Does the price include removing the old shingles?
In these rates, one layer and its disposal, yes. On a quote, only if it says so. Ask, and ask what a second layer costs if the roofer finds one.
Do I need a permit to replace my roof?
Usually not for like-for-like re-roofing without structural work; Toronto says so explicitly, and most municipalities follow. Changing the structure, adding a dormer or a skylight opening, or re-roofing a heritage-designated house is different. Your building department answers in two minutes.
When is the best time to replace a roof in Ontario?
Late spring to early fall, above 10 C so the shingle seal strips bond. Roofers are busiest in June to September and cheapest in April and October. A roof can go on in November on a mild week; it cannot be done properly at -10 C. Page: when to replace a roof.
Is the estimate an offer or a price?
Neither. It is a budgeting allowance so you walk into the conversation knowing what the number should look like. Only a roofer’s written quotation after walking the roof is a price.
Before you sign anything
Three quotes on one written scope. The product named, the flashing new, the decking unit-priced, the ventilation planned. Ten to fifteen percent down, the balance when the magnet has been over the lawn. And a copy of the WSIB clearance before anyone climbs a ladder.
