What a Cost-of-Living Adjustment Actually Measures (and What It Leaves Out)

“Is $120,000 there worth more than $150,000 here?” is the question every cost-of-living calculator promises to answer. Very few of them tell you how. Most run your salary through a proprietary index — a blend of crowdsourced price reports, scraped listings, and undisclosed weights — and return a number you cannot verify. There is a federal alternative, and it's one division.

The federal price index: Regional Price Parities

The Bureau of Economic Analysis publishes Regional Price Parities (RPPs) — an index of how price levels in each state compare to the national average, with the U.S. set to 100. A state at 112 is 12% more expensive than the national average across all consumption; a state at 91 is 9% cheaper. The all-items index is built from the same price data BLS collects for the Consumer Price Index, combined with housing rents from the Census Bureau's American Community Survey — measured prices, not volunteered ones. The current vintage is 2024, published annually.

The entire calculation, in one line

To find the salary in state B with the same purchasing power as your salary in state A: equivalent = salary × (RPP of B ÷ RPP of A). That's it. $150,000 in a state at RPP 110, moved to a state at RPP 92, needs 150,000 × (92 ÷ 110) ≈ $125,500 to buy the same basket. The cost-of-living salary calculator on this site does exactly this and nothing else — both index values are shown, so every result can be checked by hand. No proprietary blend, no second data source mixed in, no adjustment you can't see.

What the adjustment leaves out — and why it matters

Taxes. RPPs compare pre-tax purchasing power. State income tax differences are material — moving between a no-income-tax state and a high-tax state can shift take-home pay by several percent in either direction, entirely outside what a price index measures. Treat the adjusted salary as a prices-only comparison and run the tax question separately.

Within-state variation. A statewide index averages a state's priciest metro with its cheapest rural counties. BEA discontinued its metro-level RPP series after 2023, so state-level is the finest current federal resolution — which means a statewide figure understates costs in, say, the Bay Area relative to the California average. A calculator that claims current city-level federal precision is claiming data that no longer exists.

Your basket isn't average. The all-items index weights housing, goods, and services the way the average consumer buys them. If your spending is dominated by one category — rent especially — your personal cost difference between two states can be larger or smaller than the index implies.

Why this site never RPP-adjusts a wage figure

Every BLS wage on WageTruth is published as a nominal figure, and it stays that way — the calculator deflates only the salary you type in. Blending a price adjustment into cited wage data would produce numbers BLS never published, which is precisely the practice this site exists to avoid. If you're comparing what an occupation actually pays across cities, the metro comparison shows the published nominal distributions side by side; this calculator is the separate, clearly-labeled step for translating one of those figures into your destination's prices. For the background on reading those nominal comparisons, see comparing pay across cities.

Informational only, not professional or financial advice.