Our cost ranges are built from federal wage data and current published material pricing — not copied from anyone else's cost guide. Here is the whole method.
The ranges in our cost calculators are calculated, not collected. We price the materials a job actually needs, add the labor hours it actually takes at the wage that trade actually earns in the United States, and then account for the fact that a contractor has to cover insurance, vehicles, overhead and profit on top of that. That is the method this page documents.
Be clear about which figures those are. The eight cost calculators run the model live in your browser and recompute for your metro. The ranges you see elsewhere — on city pages, state pages, vertical guides and in article prose — are researched ranges: what the market charges, gathered per city and per trade, and sanity-checked against this model rather than produced by it. They will not always match the calculator to the dollar, and where they differ the calculator is the one whose arithmetic you can inspect below.
We publish a range rather than a single number because the honest answer spans a wide market. The low end reflects a lean independent contractor fitting mid-grade material. The high end reflects a national in-home-sales company fitting premium material. Both are real prices that real homeowners pay for the same nominal project.
These are planning estimates, not quotes. No formula can see your house. Get at least three written quotes before you commit to anything.
That last line is the one most cost guides leave out, and it is the reason online estimates so often come in below real quotes. A contractor does not bill you their cost. They bill you their cost plus everything it takes to run a business that shows up.
| Input | Source | How confident we are |
|---|---|---|
| Hourly wages | US Bureau of Labor Statistics, Occupational Employment and Wage Statistics, May 2025. We use the specific trade for each job — roofers for roofing, glaziers and carpenters for windows, plumbers for bathrooms, sheet metal workers for gutters. | High. A federal survey of actual wages, updated annually, free to anyone. |
| Material prices | Current listed prices from retailers and manufacturers, captured on a stated date. We record the product, the price and the page for every single one. | High for the price itself. Note that retail is not contractor pricing — contractors buy at a trade discount but mark materials up, and the two effects broadly offset. |
| Employer cost load | BLS Employer Costs for Employee Compensation. Wages are about 67% of what a construction employer actually pays per hour worked; the rest is payroll tax, insurance and benefits. | High. Also federal data. |
| Labor hours | Published installation references and trade sources where they exist. Where they do not, we state our own assumption rather than dress it up. | This is our weakest input. See below. |
| Overhead & profit | Our own assumption, expressed as a range from lean independent contractor to national in-home-sales company. | Assumption. It is the single biggest driver of the final number. |
Most cost guides do not have a section like this. We think that is a mistake, so here is ours.
Labor hours are genuinely hard to source. Trade associations publish detailed standards for how to install a product — fastener patterns, flashing details, clearances — but almost none of them publish how many hours it takes or how many people it needs. Where we could not find a published figure, the hours in our model are our own estimate, cross-checked against what contractors describe. That is an honest gap and we are working to close it against a published estimating reference.
Two line items have no public price at all. Subfloor preparation and tearing out an existing floor are quoted separately by nearly every flooring contractor, and no one publishes what they cost. That absence is worth knowing about: if a flooring quote comes in far above the per-square-foot price you saw advertised, this is usually why.
Local variation is real and we are still improving how we handle it. Labor is the part of a job that varies most by market, and wages differ substantially between metros. We are moving our city pages onto per-metro federal wage data so that a local estimate reflects local labor rather than a blanket adjustment.
We do not republish anyone else's cost data. Several well-known cost datasets are licensed products, and their terms do not permit dropping them into a calculator or a database. Building our own model from public wage data and published prices means we can show you the arithmetic instead of asking you to trust a number we borrowed.
We do not quietly change our numbers. Wages refresh annually when the BLS publishes. Material prices are re-captured on a stated schedule and adjusted between refreshes using the federal producer price index for construction materials.
We do not pretend a range is a quote. Every cost figure on this site is a planning estimate. The only number that reflects your actual home is a written quote from a contractor who has seen it.
These are the questions homeowners ask most often before starting this project - what it costs, how long it takes, what a fair quote looks like and which details change the price. Each answer below is written to stand on its own, so you can read just the one you need.
Method version: 2026-08-12 ·Wage data: BLS OEWS, May 2025 ·Material pricing captured: 2026-08-12
Questions about the method, or think an input is wrong? We would rather hear it — contact us and say which number and why.
