Measure your roof size and squares

How to use your roof size

1. Measure your roof above and note the total area in square feet.
2. Divide by 100 to get roofing squares (for example, 2,400 sq ft = 24 squares).
3. Find the squares listed on each estimate and compare them with your number.
4. If an estimate is far off, ask the roofer how they measured and what waste allowance they added.

Want a second set of eyes on the whole estimate? Send your estimate for review or read our roofing estimate red flags.

Roof size questions

What is a roofing square?

Roofers price by the square. One square equals 100 square feet of roof surface, so a 2,500 sq ft roof is 25 squares.

Why is roof area bigger than my home's floor area?

Roof area includes the slope (pitch) and the overhangs past the walls. A steeper roof has more surface than the footprint underneath it.

Why check the roof size on an estimate?

Most of a roofing price scales with the number of squares. If one estimate lists noticeably more squares than another for the same house, ask the contractor to explain how they measured.

What about waste?

Estimates usually add a waste allowance for cuts, hips and valleys. It should be stated separately so you can see the measured area versus the material ordered.

Is an online measurement exact?

No. It's a good cross-check, but a contractor's on-site measurement is what the final price should be based on.