How to read a cost estimate

Estimate, quote, bid

• An estimate (like the ones on this site) is a range based on typical jobs.
• A quote or bid is a contractor’s price for your job, after seeing it. Ask for it in writing.
• A change order is a later addition to the job, and it is where budgets often grow.

Why costs are ranges

Costs differ for reasons no website can see: access, condition of what is underneath, local labor rates, material grade, how busy contractors are. Published cost guides also use different data and methods, so they often disagree. For asphalt roofing, for example, one guide gives $3–$6 per square foot and another $4.25–$12.25. ^{[1] [2]} We show both instead of averaging them.

What to check in a quote

1. Scope. What exactly is being done, and what is not?
2. Materials. Brand, grade, and quantity.
3. Removal and disposal. Tear-off and hauling are often separate lines.
4. Permits and inspections. Who pays and who arranges them?
5. Warranty. On materials and on workmanship, and for how long.
6. Unknowns. What happens if hidden damage is found? How is the extra priced?
7. Payment schedule. Be cautious about large payments before work starts.

Comparing quotes

Get at least three. Make sure they describe the same work. The cheapest quote is not a bargain if it leaves things out, and the dearest is not automatically better. Ask each contractor to explain the difference between theirs and the others.

Using the numbers on this site

Treat our ranges as a sanity check before you call anyone, so you know when a quote is far outside the normal band and worth questioning. They are not a substitute for a local quote. See how we work out costs. For worked examples of ranges, drivers and exclusions, see how much a new roof costs and how much it costs to insulate an attic. If a quote is high, should I repair or replace it? can help you decide.

Sources & methodology

1. Roof Replacement Cost — HomeGuide Cost guide (crowd/contractor data)Installed $/sq ft by material, tear-off labor, and the $5,400–$17,400 spread by state. Updated Nov 2025. Scope: US national. Published or updated: Nov 2025. Accessed October 4, 2026.
2. Cost to Replace Roof Shingles — NerdWallet Cost guide (crowd/contractor data)Asphalt $4.25–$12.25 per sq ft; permits, inspection, flashing and tear-off as extras. Updated Jul 2025. Scope: US national. Published or updated: Jul 2025. Accessed October 4, 2026.