How to Bid a Roof, Step by Step
Roofing is priced by the square, not the hour. Get the square count right and the rest is arithmetic.
One square = 100 square feet of roof surface (not floor area). Measure each plane, account for pitch, and add 10 to 15 percent for waste on cuts, hips, and valleys. Satellite measurement tools or a drone speed this up and reduce climb risk.
Installed per square: asphalt $350 to $550, flat membrane (TPO/EPDM) $400 to $800, standing-seam metal $900 to $1,600. This is labor plus materials for a straightforward roof.
Layer in tear-off and disposal, a steep or cut-up premium, permit, and any decking or flashing repairs. Then add your markup. Quote one job number with the scope written out so there's no argument later.