What is a roofing square?
A roofing square is a unit of measurement equal to 100 square feet of roof area, used by contractors to calculate material quantities and provide estimates.
Contractors and material suppliers across Ontario use the roofing square as the standard measurement unit when pricing shingles, underlayment, flashing, and other roof coverings. One square equals 100 square feet of roof surface, which simplifies takeoffs and allows quick conversion between area measurements and bundle counts.
When a roofer measures your roof, they calculate the total area in square feet, then divide by 100 to determine how many squares of materials are needed. A typical bundle of asphalt shingles covers one square. This system makes it faster to quote jobs, order supplies, and track labor costs, since both material waste and installation time scale predictably with the number of squares involved.
You will see this term on every estimate from roofing contractors in Ontario. Understanding that a square represents 100 square feet helps you compare quotes accurately and ensures you know exactly how much material coverage your roof requires. It is also the basis for calculating how many shingles, strips of ice and water shield, or rolls of synthetic underlayment a project will demand.