How the cost of living calculator works
Most cost-of-living calculators multiply your salary by the ratio of two price indexes. That misses the two things that move a household budget most when you relocate: taxes and the specific costs of your household — the rent for the number of bedrooms you need, childcare for your children’s ages, and how much you drive. MoveMath builds the whole budget, line by line, in both places, and then asks one question: what salary in the new place leaves you with the same amount of money each month?
Worked example: New York, NY-NJ to Austin, TX
The comparison above loads with a single adult earning $75,000 who rents, drives one car 12,000 miles a year at 25 mpg, buys food on USDA’s Moderate-Cost plan and spends $500 a month on other goods and $500 on other services at US-average prices. The numbers below come from the same engine as the calculator.
| Monthly | New York, NY-NJ | Austin, TX |
|---|---|---|
| Taxes (federal, FICA, state, local) | $1,641 | $1,117 |
| Rent (1-bedroom HUD Fair Market Rent) | $2,729 | $1,530 |
| Food, fuel, sales tax and other spending | $1,763 | $1,547 |
| Left over | $117 | $2,055 |
On the same salary this household would have +$1,939 a month in Austin, TX. Solving for the salary that keeps the $117 a month it has in New York, NY-NJ gives $44,991, or −40.0%. Taxes take 26.3% of income in New York, NY-NJ and 17.9% in Austin, TX. Full metro profiles: New York, NY-NJ and Austin, TX.
What goes into each line
| Line | Official source | How we use it |
|---|---|---|
| Income taxes | IRS and state revenue departments (2026) | Annual liability: federal tax with the standard deduction and Child Tax Credit, Social Security and Medicare, state income tax, state payroll taxes, and the principal city’s (or county’s) mandatory local income tax. |
| Rent | HUD Fair Market Rents FY2027 | The 40th-percentile gross rent for the bedroom count your household needs. Option: Census ACS median gross rent (all unit sizes). |
| Mortgage and property tax | Census ACS 2020-2024 | Your price, or the metro’s median home value; property tax uses the effective rate = median taxes paid ÷ median value. Insurance is your input. |
| Childcare | DOL National Database of Childcare Prices (2022) | The principal county’s weekly median price for each child’s age band and care type, times the weeks you enter; optionally brought to current dollars with the BLS day-care price index. Where the county has no 2022 price the latest published year (2020 or 2021) is used and labelled; where DOL has no price at all (Indiana, New Mexico, most of Missouri) childcare is left out with a warning. |
| Food | USDA Food Plans (August 2026) | Monthly cost for each household member on the plan you choose, with USDA’s household-size adjustment, scaled by the metro’s BEA price parity for goods. |
| Utilities (owners) | EIA average residential electricity bill by state | The state’s average monthly bill, or your kWh × the state’s average price; natural gas at the state price × your usage. |
| Gasoline | EIA weekly retail prices | Miles ÷ mpg × the state price (9 states) or the regional (PADD) price. |
| Sales tax | State revenue departments | The state rate on your other goods, plus groceries where the state taxes them. Local add-on rates are not modeled. |
| Other goods and services | BEA Regional Price Parities 2024 | Your monthly baseline at US-average prices, scaled by the metro’s goods and other-services price parities. This is an estimate, not a measured cost. |
How the salary needed is solved
The engine first computes what is left over in your current metro: gross income, minus every tax, minus every modeled cost. In the new metro the costs don’t depend on your salary, but taxes do, and they are progressive and differ by state and city. So the calculator searches for the salary: it tries an income, runs the full 2026 tax engine for the new place, subtracts the new place’s costs, and narrows the range by halves until the amount left over matches your current one to within a dollar. Because no tax takes 100% of an extra dollar, the amount left over always rises with income, so the search always lands on a single answer. Two-earner households keep the same split between earners.
Why the answer can surprise you
- Taxes scale with the raise. If the new place costs $500 a month more, you need more than $6,000 a year extra, because part of every raise goes to tax — more in high-tax states and cities.
- Rent dominates. Housing price differences between metros are far larger than differences in goods prices, so the bedroom count matters a lot.
- Childcare can outweigh rent. In 168 of the 366 metros with county price data, a year of center-based infant care (in current dollars) costs more than a year of rent on a 1-bedroom at Fair Market Rent.
What the calculator leaves out
We only model what official data supports. Not included: health insurance premiums and out-of-pocket care, car payments, insurance and maintenance, local sales tax add-ons, itemized deductions and credits other than the Child Tax Credit, and moving costs. Add any fixed monthly costs you know about in “Fixed costs / month” — they are counted the same in both places. The 2026 income-tax figures are annual-liability estimates, not paycheck withholding. Metros outside the 50 states and DC (Puerto Rico) are not covered because our tax data does not include Puerto Rico’s income tax. See the methodology for every source, vintage and limitation.