Roof Shingle Calculator (Canada)
Free Canadian roof shingle calculator. Compute total shingle pieces, bundles, starter strip, and ridge cap from footprint, pitch, and waste — for IKO, BP, GAF, CertainTeed, and Malarkey laminate shingles.
Roof Shingle Calculator
Calculate the number of shingles, bundles, starter strip and ridge cap pieces for your project.
How this Canadian roof shingle calculator works
Enter the building footprint length and width (in feet — Canadian residential plans are typically imperial), the eave overhang, the pitch in X/12, and the waste percentage. Pick the shingle type — 3-tab, architectural laminate, designer, or cedar shake — and the calculator returns the surface area in sq ft, the squares, the total shingle pieces, the bundle count, starter strip pieces, ridge cap pieces, and a material-only cost in CAD.
The math, derived from first principles
slope factor = √(1 + (rise/run)²)
roof area = (length + 2×overhang) × (width + 2×overhang) × slope factor
pieces = (roof area / 100) × pieces-per-square × (1 + waste %)A 30 × 40 ft Canadian bungalow with 1 ft overhang at 6/12 pitch has a roof surface of 1,503 sq ft = 15.03 squares. At 64 pieces/square (IKO Cambridge architectural) and 10% waste, that is 1,058 shingles, or 50 bundles at 21 pieces per bundle.
Pieces per square — Canadian product reference (2026)
Densities verified against IKO, BP, GAF Canada, CertainTeed Canada, and Malarkey Canadian distributor data:
| Shingle | Pieces / bundle | Bundles / sq | Pieces / sq | C$ / square installed |
|---|---|---|---|---|
| 3-tab (IKO Marathon, BP Yukon SBS) | 27 | 3 | 80 | C$520–C$680 |
| Architectural (IKO Cambridge, BP Mystique) | 21 | 3 | 64 | C$680–C$870 |
| Architectural (GAF Timberline HDZ, CertainTeed Landmark) | 21 | 3 | 64 | C$720–C$920 |
| 50-yr laminate (IKO Dynasty, IKO Crowne Slate) | 21 | 3 | 64 | C$820–C$1,050 |
| Designer (IKO Royal Estate, GAF Glenwood) | 18 | 4 | 56 | C$1,180–C$1,500 |
| Cedar shake (#1 medium, BC) | 25 | 8 | 200 | C$1,450–C$2,000 |
Prices include HST and reflect the 2025-26 IKO Plus / BP Pro contractor program rates. HomeStars and TrustedPros quote installed rates of C$4.50–C$7.50 per sq ft for IKO Cambridge architectural — the dominant Canadian product.
Common mistakes
Skipping the ice and water shield calculation. NBC 2020 Section 9.26.5 requires ice barrier from eave to at least 36 in past the inside face of the exterior wall in heated buildings. In Quebec (CCQ) and Ontario (OBC) the requirement is identical. Order it as a separate line — the calculator’s ridge and starter outputs do not include ice barrier rolls.
Forgetting the eave starter requirement. IKO and BP both require manufacturer starter strip on architectural shingles for the wind warranty (which is 130 km/h on Cambridge, 200 km/h on Dynasty Performance). Cutting starter from cut 3-tabs voids the warranty in writing.
Under-counting cap on hip roofs. Architectural ridge cap covers ~1 lf per piece. A 30 × 40 hip roof has roughly 28 ft of ridge plus 4 hip lines × 18 ft = 100 ft of cap total, not just 28. The calculator returns the right count once you enter ridge and hip lengths.
Plywood decking sized from footprint, not surface area. When re-decking, the OSB or plywood sheets follow the surface area, not the ground footprint — same pitch correction as the shingles.
Code references
- NBC 2020 — Section 9.26 (roofing), 9.26.5 (ice barrier), 9.26.6 (asphalt shingle installation).
- NECB 2020 — energy compliance affecting attic insulation when reroofing.
- CSA A123.1 / A123.21 — asphalt shingle physical requirements (the Canadian counterpart of ASTM D3462) and wind resistance (A123.21 corresponds to ASTM D7158).
- CRCA Roofing Specifications Manual — current edition for installation method and waste guidance.
- Provincial codes — Ontario OBC, BC BCBC, Quebec CCQ, Alberta ABC — all reference NBC 9.26 directly with regional amendments for snow load and ice damming.
Industry references: Canadian Roofing Contractors Association (CRCA), CASMA (asphalt shingle manufacturers), HomeStars, Renomii, TrustedPros.
How this calculator differs
The calculate-roofing material takeoff gives a full reroof bill — shingles, underlayment, ice & water shield, drip edge, valley flashing, OSB decking and nails. This shingle calculator returns only the shingle-product line items, which is what your shingle supplier (Beacon, ABC Supply Canada, BMR, Home Hardware Building Centre) quotes from.
Putting it together
Run the calculator, write down the bundle and ridge cap counts, and cross-check with the roof cost calculator for an installed budget and the roof area calculator for shape comparisons. A typical Canadian 1,500 sq ft surface area reroof in IKO Cambridge runs C$1,800–C$2,500 in shingle materials and C$8,000–C$12,000 installed including tear-off, ice and water shield, and crew labour.
Get the shingle count right at the takeoff stage and the project schedules cleanly. Pull a building permit through your municipal e-permit portal — most provinces require it for any reroof — and your installer can quote off the exact same numbers.