How We Calculate

Last updated: 2026-10-22

Every calculator uses a published or widely accepted trade formula. For example, board feet use thickness x width x length / 12, stair layouts use equal risers from the measured total rise, and coverage tools use typical manufacturer coverage rates.

Where code limits are mentioned we base them on the National Building Code of Canada and tell you when provinces such as Ontario, British Columbia, Alberta and Quebec may differ. Costs, where shown, are broad CAD ranges and not quotes.

Pages are checked when published and reviewed when codes, standards or common product sizes change. If you spot an error, please tell us through the contact page.