Pricing a roof per square metre in Canada: rates, taxes and quotes
How Canadian roofers price a roof per m²: converting a per-square rate, which items go per lineal metre, and the taxes on the discounted subtotal, worked on a Québec quote.
Pricing a roof per square metre in Canada comes down to one formula: true roof area in m², with waste on the materials, times your rate per m², plus the lineal-metre items, less any discount, plus your province's GST, HST or PST. The rate is yours. What usually goes wrong is the conversion, the unit each line is measured in, and where the tax lands.
This guide builds one metric quote line by line, in Canadian dollars, so you can check it.
Why Canadian roofers quote per square metre
Most residential roofers in Canada still think in squares. Metric pricing shows up when the job does:
- Tenders and commercial specs. Public and institutional work across Canada, from Ontario school boards to federal buildings, is usually specified in metres and m², and bid forms want a rate per m².
- Metric plans. When the drawings are in millimetres, pricing in m² keeps the takeoff and the quote on the same unit.
- Comparable quotes. A general contractor comparing three roofing bids in m² does not want to convert yours.
You do not need a new pricing model. You need your per-square numbers expressed per m², and a clean split between area items and length items.
Converting a per-square rate to per m² in Canada
One square is 100 ft², which is 9.290 m². So:
- Per square to per m²: divide by 9.290.
- Per m² to per square: multiply by 9.290.
Example rates, not market prices: a rate of $500 per square is 500 ÷ 9.290 = $53.82 per m². A rate of $50 per m² is 50 × 9.290 = $464.50 per square.
Do not round a square to 10 m². That makes every per-m² rate about 7% low, and the error hides because the number still looks reasonable.
What to price per m², and what per lineal metre
A metric quote reads cleanly when every line uses the unit it is measured in.
| Line | Unit | Measured on |
|---|---|---|
| Tear-off and disposal | m² | True area, no waste |
| Shingles and underlayment | m² | True area plus waste |
| Eave membrane | m or m² | Eave length, code width |
| Drip edge and starter | lineal m | Eaves and rakes |
| Hip and ridge cap | lineal m | Hips plus ridge |
| Valley, step and wall flashing | lineal m | Each run |
True area is plan area times the pitch factor (5/12 is 1.083, 6/12 is 1.118, 8/12 is 1.202). Charge tear-off on what comes off the roof, not on the material you order, so leave waste out of that line. The roof square footage calculator gives you the area, and the price per square calculator shows the same job priced by the square.
On eave membrane, the National Building Code of Canada and each province's own edition set a minimum distance up the slope, so the width per lineal metre depends on the overhang and the wall. Check the edition that applies to the job.
Worked example: a Canadian quote in square metres, Québec taxes
A gable bungalow in Laval, Québec. Footprint over the overhangs 12.0 m × 9.0 m, pitch 6/12.
Measurements
- Plan area: 12.0 × 9.0 = 108.0 m²
- True area: 108.0 × 1.118 = 120.7 m²
- With an example 10% waste: 120.7 × 1.10 = 132.8 m²
- Eaves: 2 × 12.0 = 24.0 m
- Rakes: each 4.5 m run × 1.118 = 5.03 m, four of them = 20.1 m
- Drip edge and starter, eaves plus rakes: 44.1 m
- Ridge: 12.0 m
The quote, in Canadian dollars (example rates, not market prices)
| Line | Quantity | Example rate | Amount |
|---|---|---|---|
| Tear-off and disposal | 120.7 m² | $12.00/m² | $1,448.40 |
| Shingles and underlayment, installed | 132.8 m² | $45.00/m² | $5,976.00 |
| Eave membrane | 24.0 m | $18.00/m | $432.00 |
| Drip edge and starter | 44.1 m | $9.00/m | $396.90 |
| Ridge cap and vent | 12.0 m | $25.00/m | $300.00 |
| Subtotal | $8,553.30 | ||
| Discount 5% | −$427.67 | ||
| Discounted subtotal | $8,125.63 | ||
| TPS (GST) 5% | $406.28 | ||
| TVQ (QST) 9.975% | $810.53 | ||
| Total | $9,342.44 |
Both taxes are calculated on the discounted subtotal, side by side. The TVQ is not charged on the TPS.
Check it per m² of true area: $8,125.63 ÷ 120.7 = $67.32 per m² before tax. That all-in number is what a general contractor will compare against other bids, so know it before you send.
Taxes on a roofing quote in Canada
Sales tax on a Canadian roofing quote depends on the province where the work is done:
- Québec: TPS (GST) 5% and TVQ (QST) 9.975%, both on the price before tax, as in the example.
- Everywhere else: your province's GST, HST or PST. Rates and rules differ between provinces and change over time, so take them from the Canada Revenue Agency or your provincial tax authority, not from a blog post.
Two habits keep tax lines clean. Apply the discount first, then tax the discounted subtotal. And print each tax on its own line, with its name, so the customer in Alberta or the Atlantic provinces sees the tax they expect.
Building the metric estimate in RoofStruct
Measuring is free: free, unlimited self-serve measuring and PDF reports, no card. Search the Canadian address, trace the roof on satellite imagery or your own drone or phone photo in minutes, and set Settings › Localization › Measurement Units to Metric so areas and lengths come out in m² and m.
On Pro, estimates can be in Canadian dollars and priced per square or per m². A Québec (TPS + TVQ) tax mode applies TPS 5% and TVQ 9.975% to the discounted subtotal, the way the example above does. RoofStruct's own plans are billed in US dollars; the estimates you send can be in Canadian dollars. The app runs in English and Canadian French.
For the full path from a report to a price, see how to price a roofing job from a measurement report.
Where you trip pricing per m² in Canada
Rounding the square to 10 m². Every converted rate comes out about 7% low.
Charging tear-off on the waste. Waste is material you buy, not roof you strip. Tear-off goes on true area.
Pricing plan area. A 108 m² footprint at 6/12 is 120.7 m² of roof. Quote the footprint and you give away the slope.
Taxing before the discount. Tax goes on the discounted subtotal. Taxing first and discounting after leaves the tax lines wrong.
Hard-coding one province's tax. A crew working Ottawa and Gatineau in the same week quotes under two tax regimes. Set the tax per job.
FAQ
How do I convert a price per square to a price per square metre?
Divide by 9.290. With example rates, not market prices: $500 per square is $53.82 per m².
Should waste be included in the per-m² price?
Put waste in the material quantity, not in the rate. Then tear-off stays on true area and the customer sees honest quantities.
Is the TVQ calculated on the TPS in Québec?
No. Both are calculated on the price before tax: TPS at 5% and TVQ at 9.975%.
What tax goes on a roofing quote outside Québec?
Your province's GST, HST or PST. Check the current rate with the Canada Revenue Agency or your provincial tax authority before you send.
Can I quote in Canadian dollars per m² in RoofStruct?
Yes, on Pro: estimates can be in Canadian dollars and priced per square or per m², with a Québec (TPS + TVQ) tax mode.
Sources
Checked Oct 2026: