Arithmetic resultCanada-wide arithmetic

Roofing Materials Calculator

Estimate sloped roof area and product quantities for a simple roof footprint. No snow-load or member-sizing advice.

roofing-materials@1.0.0

Project Passport

My renovation plan · Toronto, Ontario

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01 · Project measurements

Adjust the inputs and the result updates immediately. Every prefilled measurement is an editable starting example, not a fact about your project.

Roof footprint lengthmRoof footprint widthm

Pitch risePitch run

Waste allowance%Editable default

Technical assumptions

Bundle coveragem²Editable defaultUnderlayment roll coveragem²Editable default

02 · Planning result

Source-backed method

Order area

77.56 m²

Roof footprint

66.89 m²

Pitch multiplier

1.05

Net sloped area

70.51 m²

Roofing squares

8.35

Bundles

Underlayment rolls

Export

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Assumptions

These are part of the result, not fine print.

The roof is modelled as one simple pitched footprint without dormers, valleys or hips.
Editable waste allowance: 10%
Entered coverage per bundle: 3.0967680000000004 m²
Entered coverage per underlayment roll: 37.161216 m²

Quantity only: this result does not assess structure, snow load, ventilation, membranes or code compliance.
Product counts use the entered package coverage; verify each manufacturer label.

Planning information only. This is not a quote, code-compliance decision, structural recommendation, or substitute for site review.

Government of Canada, Department of Justice

Canadian SI, yard, foot, inch, area and volume unit definitions

Version: current-to-2026-06-14CanadaR.S.C., 1985, c. W-6; page current to 2026-06-14Source-backedLast reviewed: 2026-08-01

Orion Project Studio

Geometry-only material quantity calculation contract

Version: 1.0.0Canada1.0.0Source-backedLast reviewed: 2026-08-01

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