Composite cost of living: -9.4% between Denver and Chicago. Equivalent of $75,000 in Denver: about $67,969 in Chicago. Housing alone moves -20.5%, the dominant driver per C2ER ACCRA's quarterly cost-of-living publication.
Salary-equivalence math is the same across every cost-of-living comparison: scale by index ratio. For Denver (128) to Chicago (116) that ratio is 0.906. The table below applies it to the three anchor incomes most relocators use as decision points.
| Denver salary | Equivalent in Chicago | Difference |
|---|---|---|
| $50,000 | $45,313 | -$4,687 |
| $75,000 | $67,969 | -$7,031 |
| $150,000 | $135,938 | -$14,062 |
The breakdown below decomposes the Denver-vs-Chicago cost-of-living gap into its five constituent sub-indexes. National average for each is 100; the delta column shows how each line item changes between the two metros. Housing routinely shows the largest swing.
| Category | Denver | Chicago | Delta |
|---|---|---|---|
| Housing Rent + median home price | 166 | 132 | -20.5% |
| Groceries Supermarket basket | 102 | 100 | -2.0% |
| Transportation Fuel, transit, parking | 105 | 108 | +2.9% |
| Healthcare Doctor visits, prescriptions | 104 | 99 | -4.8% |
| Utilities Electric, gas, internet | 96 | 112 | +16.7% |
| Composite | 128 | 116 | -9.4% |
Denver, CO versus Chicago, IL: the composite cost-of-living index difference is about -9%, putting the move in the "lateral" zone where lifestyle, climate, career, and tax factors usually outweigh pure cost considerations. At this scale of gap, the noise inside the index (sampling variation, year-over-year price drift, individual basket differences) is roughly the same size as the signal between the two cities.
What is worth checking: are there meaningful state-tax differences between Colorado and Illinois? Is the housing sub-index gap larger or smaller than the composite gap, indicating that the categories you actually spend on diverge from the average mix? The sidebar and the tables below break out these dimensions so you can stress-test whether the lateral classification holds for your specific situation.
State income tax is not part of the cost-of-living composite, but it is part of your real take-home math. Colorado's effective top rate is 4.40%; Illinois's is 4.95%. On a $75,000 salary the two states pull $3,300 and $3,713 respectively — a gap of $413 that compounds with the consumer-price difference.
Model the precise after-tax difference with the take-home pay calculator using your specific filing status and salary. Federal tax is identical regardless of which state you live in; only the state component moves. See the take-home pay calculator or the state-by-state take-home pay article for the precise after-tax number.
The data says no. Composite indexes: Denver 128, Chicago 116. Chicago is roughly 9% less expensive overall, with the housing sub-index doing most of the work and other categories contributing smaller deltas.
Roughly $67,969 per year in Chicago matches what $75,000 buys in Denver, based on the C2ER ACCRA composite ratio of 0.91. The result is pre-tax — add the state-tax delta from the sidebar for the full after-tax comparison.
Housing is the largest line item in any cost-of-living comparison and the one with the most metro-to-metro variance. Denver's housing sub-index sits at 166; Chicago's is 132. That gap reflects rent and home-price differences captured in the C2ER ACCRA quarterly survey. Groceries (Denver 102 vs Chicago 100), transportation (105 vs 108), and utilities (96 vs 112) all contribute, but housing is the dominant factor.
They are tracked separately. The cost-of-living composite measures consumer prices; state income tax is a different axis. Colorado and Illinois can disagree on tax by several thousand dollars per year at typical salaries, and that delta stacks with — not into — the consumer-price gap above.