Glossary
Roofing square
A roofing square is a unit of roof area equal to 100 square feet, used to quantify materials and labor on a roof.
A roofing square is a unit of roof area equal to 100 square feet, used to quantify materials and labor on a roof.
Roof area is calculated from the footprint and the slope, then divided by 100 to get squares. Waste is added on top, commonly 10% to 15% depending on how cut up the roof is.
Ordering by squares rather than square feet is standard in the trade because bundles of shingles are sold in fractions of a square.