Roofing Square
A unit of measurement equal to 100 square feet of roof surface area.
The Unit Contractors Use
A roofing square equals 100 square feet of roof area — not 100 square feet of your home's footprint, since roof pitch adds surface area beyond the building's floor plan. Materials (shingles, underlayment, ice-and-water shield) and most contractor bids in Ohio are priced per square, so a bid quoted as "$450/square" on a 22-square roof comes to $9,900 before add-ons like decking or flashing.
Why the Estimate Can Vary Between Contractors
Two contractors measuring the same roof can arrive at different square counts if one uses satellite/aerial measurement software and another does a rough ground estimate, or if they calculate pitch differently — a steep roof has significantly more actual surface area than its footprint suggests. Always ask for the measured square count in writing, not just a lump-sum price, so you can compare bids apples-to-apples.