Roofing
Roof Shingle Calculator
Estimates roof shingles or shingles by pitch and area
Updated June 26, 2026 · Live
What this tool does
Estimates roof shingles or shingles by pitch and area. Squares and m².
Formula Used
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How the roof shingle / shingle calculator works
Estimates roof shingles or shingles by pitch and area. Squares and m². The calculator takes your dimensions and supplier rates, applies a standard Canadian trade formula, and returns a quantity with an indicative cost. Every figure is an estimate — site conditions always move the final number.
Typical Canadian roofing wastage
Standard Canadian roofing wastage is 5–10% for plain tiles and 10–15% for slates or interlocking profiles, rising on complex hipped roofs and around valleys. Our defaults reflect common Canadian trade allowances, and can be adjusted upwards for non-standard geometry or downwards where experience supports a lower figure.
What this tool does not do
It does not replace a professional quote, factor regional pricing, assess structural adequacy, or confirm National Building Code (NBC) compliance. Those remain the responsibility of a suitably qualified designer, surveyor, or your building inspector.
On-site considerations for roof shingle / shingle
Working at height needs proper edge protection and a risk assessment under the Work at Height Regulations 2005. Roof safety systems are a legal requirement on commercial work and strongly recommended for domestic.
the National Building Code (NBC) and compliance
Roof coverings, insulation upgrades, and structural changes to rafters fall under Approved Documents A, C, and L. A re-roof that exposes more than 25% of the roof slope typically triggers thermal upgrade obligations. When in doubt, a pre-application enquiry to the municipality can give early clarity, which tends to be less costly than retrospective correction.
Before you order
Tile colour shifts between production runs, so a single batch number across the whole roof keeps the finish consistent. Keep a few dozen spares for future repairs. Cross-checking the calculator’s output against a supplier quote helps catch differences in pricing assumptions — ask for exact product specifications (grade, finish, batch number) and confirm delivery timescales against your programme.
Adjusting the defaults
Every input in this calculator is editable. Enter your own dimensions, supplier prices, and wastage allowance — the output recalculates instantly. If the defaults feel off for your region or project type, your own numbers always override them.
Using this roof shingle / shingle calculator alongside other BuildMetricLab tools
This calculator works best as part of a planning workflow. Pair the quantity with our project contingency, labour-hours, and material-cost calculators to build a complete estimate before you pick up the phone to a supplier. All BuildMetricLab tools run entirely in your browser — no sign-up, no data sent anywhere, and every formula is shown on-page so you can audit the maths.
Sources & methodology
Estimates roof shingles or shingles by pitch and area. Squares and m². Every result is calculated from the values you enter, and all inputs are editable.
Frequently asked questions
Are roof shingle / shingle calculator results accurate enough to order materials?
Use them as a starting estimate only. Verifying the final quantity with your supplier or contractor before ordering is good practice — site conditions, wastage and cut-offs all affect the true figure.
What wastage percentage should I use?
The calculator defaults to the typical Canadian trade allowance for roofing. Increase it for complex cuts, awkward shapes, or first-time DIY. The default wastage allowance reflects common trade practice; values lower than the default may underestimate offcuts.
Does this replace professional advice?
No. This tool is a planning estimator. For works that affect structure, the National Building Code (NBC), property-line or shared-wall, gas, electrics, drainage to a sewer, or similar, consult a suitably qualified professional.
Can I change the unit prices?
Yes — every price field is editable. Plug in your supplier's quote to get a total that matches your project.
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