Roofing Quote Comparison Calculator
Last reviewed How we calculate
Roofing quotes are hard to compare because the totals depend on how much roof each contractor measured, and they rarely measure the same. Converting each quote to a price per square, the unit roofers themselves price in, puts them on the same footing. This does that for up to three quotes.
Compare roofing quotes per square
Turn up to three roofing quotes into a price per square so you can compare them like for like.
This calculator needs JavaScript to work. The measurements below are the ones you would need to do the sum by hand.
Lowest price per square
- Quote A, per square
- Quote B, per square
- Quote C, per square
- Lowest price per square foot
- Gap between highest and lowest
- Difference in measured size
The contractors measured the roof differently by more than 10%. Before comparing prices, ask each how they measured and what they included. A quote can look cheap because it priced less roof.
The measured sizes agree within 10%, so price per square is a fair comparison. It still does not show what each quote includes: check tear-off, deck repairs, underlayment, flashing and warranty line by line.
Price per square only compares like with like. A quote that includes new flashing, ventilation and a full tear-off is not dearer than one that leaves them out; it is a different job.
How the calculation works
Each quote total is divided by the number of squares the contractor priced. The calculator shows the lowest price per square, the gap between the highest and lowest, and how far apart the measured roof sizes are. It works in any currency, provided every quote is in the same one.
A worked example
A quote of 15,000 for 25 squares is 600 a square. A quote of 17,500 for 27 squares is about 648 a square. The totals differ by 2,500, but the price per square differs by 8 per cent, and part of the gap in the totals is simply two extra squares of roof.
When the measurements disagree
If one contractor measured noticeably more roof than another, find out why before comparing prices. One may have included a porch roof or a garage the other left out, or allowed a bigger waste factor. A quote can look cheap because it prices less roof, and the difference turns up later as an extra.
What price per square leaves out
It says nothing about what is included. Line each quote up against the same list: full tear-off or overlay, deck repairs and how they are priced, underlayment and ice barrier, new flashing, ventilation, disposal, permits, and the length and terms of the warranty. The cheapest price per square is only the best value if the job behind it is the same.
Frequently asked questions
Why do roofing quotes differ so much?
Contractors often measure the roof differently, include different work such as tear-off, deck repairs or new flashing, and price materials and overheads differently. Comparing the price per square and the measured size shows which of those is behind the gap.
What is a fair price per square?
It depends on your area, the material, the roof and the time of year, so no single figure applies everywhere. Several local quotes for the same scope of work are the best guide.
What should a roofing quote include?
The roof size in squares, tear-off or overlay, how deck repairs are priced, underlayment and ice barrier, flashing, ventilation, disposal, permits, and the length and terms of the warranty.