The problem with a national average
Most cost calculators publish one figure for the whole country. That figure is wrong nearly everywhere, and it is wrong in a specific direction: labour is the largest single cost in every trade on this site, and what a crew earns varies more by geography than by anything else.
A tree crew in OR earns $35.4/hr. In TX it is $20.44/hr. That is not a rounding difference, and a national average of $25.94/hr hides all of it.
What we do instead
Each calculator starts from a base cost for the job, then applies the things that genuinely change it — size, access, condition, add-ons — and finally adjusts for local wages.
1. The wage adjustment
We take the mean hourly wage for the occupation that does that work, in your state, from the Occupational Employment and Wage Statistics series published by the U.S. Bureau of Labor Statistics. Then:
multiplier = 0.45 + 0.55 × (state wage ÷ national wage)
Only the labour share moves. Equipment, fuel, insurance and overhead make up the rest of a job and vary far less between states, so scaling the whole price by a wage ratio would overstate the difference. That is why a state paying 40% above the national mean does not produce a quote 40% higher.
For a job in OR this works out at about +20% against the national figure, and in TX about -12%.
2. The right occupation for the trade
This matters more than it sounds. The four trades here differ by nearly two to one in what they earn, so borrowing one trade's wages for another would put a real citation underneath an invented number. Each calculator uses its own series:
- Tree removal and trimming — SOC 37-3013, Tree Trimmers and Pruners. National mean $25.94/hr, 49 states.
- Piano moving — SOC 53-7062, Laborers and Freight, Stock, and Material Movers, Hand. National mean $20.38/hr, 51 states.
- Land surveying — SOC 17-1022, Surveyors. National mean $38.57/hr, 50 states.
- Home inspection — SOC 47-4011, Construction and Building Inspectors. National mean $36.1/hr, 51 states.
The Bureau publishes an annual mean rather than an hourly one for these occupations, so the hourly figure is the annual mean divided by 2,080 — the year-round full-time figure the Bureau itself uses to compute it. Dividing back out is the exact inverse, not an approximation.
3. From your ZIP code to a state
We map the first three digits of your ZIP code to a state, using the USPS prefix ranges — 942 prefixes covering 51 states and the District of Columbia. Three digits is as far as a prefix can be trusted to stay inside one state, and it is all the precision a state-level wage figure needs.
A ZIP we cannot place, and a state the Bureau does not publish for a given occupation, both fall back to the national average. When that happens the calculator says so on screen rather than implying a local figure it does not have.
What is not verified
The base costs are not yet sourced. What a medium tree, a grand piano or a two-thousand square foot inspection costs before any adjustment comes from industry-typical figures, not from measurements we have taken.
We are collecting real prices to replace them, from public contract awards, from trade bodies, and from people who tell us what they were quoted. Each calculator calibrates one reference job; the other bands keep their ratios to it, because a large tree costing twice a medium one holds everywhere while the price of the medium one does not.
None collected yet. If you have been quoted for one of these jobs, the form at the bottom of that calculator takes ten seconds and is anonymous — it is exactly the data that closes this gap.
What an estimate is not
It is not a quote, and nobody here has seen your property. A calculator cannot know that the tree is over a conservatory, that the crawlspace floods, or that the only access is through a neighbour's gate — and those are the things that move a real price most.
Use the range to tell a reasonable quote from an unreasonable one, and get the real number from someone who has stood in front of the job.
Keeping it current
The Bureau publishes new figures once a year. When they land we re-import them, check every state against the previous year, and refuse to publish any figure that has moved implausibly — a wage that jumps more than a quarter in a year is a data error far more often than it is a pay rise. Each calculator shows the date its data was imported.
Found something wrong?
Tell us. hello@costnumbers.com. If a figure here does not match what you were quoted, the useful message says what the job was, what you paid, and in which ZIP code — that is the raw material for fixing it.