Cost Estimation Methodology

This page explains exactly where the numbers on this site come from, how they are calculated, and what they cannot tell you. It is deliberately specific about the limits of the data.

What This Data Is — and What It Is Not

There are two layers to every figure on this site, and they are not equally solid.

The national cost ranges are compiled estimates, not primary research. No survey of contractors is conducted and no bids are collected. Cost figures are assembled by comparing published pricing ranges across multiple independent sources and recording the range where they converge. They are only as good as those published sources.

The city adjustment is measured, not estimated. It comes from US Bureau of Labor Statistics metropolitan wage data — the actual published hourly wages of the trades that do this work.

Data Sources

Source	What It Provides
Published contractor and industry pricing ranges	Typical project cost ranges from contractor platforms, trade publications and remodelling cost guides. Cross-compared; the published range is used where independent sources agree.
Manufacturer and retailer material pricing	Per-unit material costs (per sq ft, per linear ft) taken from current published retail and manufacturer pricing.
BLS Occupational Employment and Wage Statistics (OEWS), May 2025	Hourly median wages, national and by metropolitan area, for the ten trade occupations this site prices — plumbers, electricians, roofers, painters, carpenters, cement masons, HVAC mechanics, tile and stone setters, floor layers, and landscaping workers. This is the source of the city labor adjustment factor across all 20 metros.

Calculation Method

Each of the 100 project types carries a national cost range. City figures are derived from it:

City Adjusted Cost = National Range × City Labor Adjustment Factor

Where:

National Range — the low/typical/high cost range for the project, compiled from the published sources above.
City Labor Adjustment Factor — the median ratio of local to national hourly wages across those ten trades, from BLS. If plumbers, roofers and tile setters in a metro each earn about 1.3× the national median for their trade, that metro's factor is 1.30. The median (rather than the average) is used so one unusual trade cannot swing a city.

Dollar amounts are rounded to the nearest $5 above $100, and to the nearest $1 at or below $100.

Known Limitations

These are the specific weaknesses of this method, stated plainly:

Wages are not prices. The factor measures what tradespeople are paid, not what contractors charge. Overhead, insurance, permit costs and local demand also move a quote, and they are not captured here.
One factor covers all trades in a city. The site applies a single metro-wide factor, but trades diverge within a metro — an electrician's premium is not an equal to a landscaper's.
Some metro/occupation cells are suppressed by BLS for small sample sizes. Where that happens, the factor is the median of the trades BLS does publish for that metro.
Compiled figures inherit their sources' errors. Where published sources disagree, the range is widened rather than a single number invented — but a range that is wrong at the source will be wrong here.
Costs are national-range based. Only labor is adjusted by city; material prices are treated as broadly national, which understates variation in remote markets.
No seasonality. Figures do not model demand peaks, and pricing in trades like roofing and HVAC moves seasonally.
Site conditions, access, scope, permit requirements and contractor availability routinely move a real quote outside the published range.

The ranges shown are a reference point for planning. They are not quotes and do not guarantee pricing from any contractor.

How This Data Is Maintained

Cost ranges are reviewed against their published sources and revised when those sources move. The date on each page reflects when that page's figures were last reviewed.
Adjustment factors are rebuilt when BLS publishes a new OEWS release, which happens annually each spring.
A page's last updated date is only moved when its figures or content actually change. It is not refreshed to look current.

Corrections

If a figure on this site is wrong, it should be corrected. Report it to [email protected] with the page and the source that contradicts it.