Overall
- Boulder
- 105.2
- Chicago-Naperville-Elgin
- 103.6
Diff -1.6 RPP
Boulder vs Chicago-Naperville-Elgin
Cost of living comparison based on BEA Regional Price Parities. Chicago-Naperville-Elgin is 1.5% less expensive than Boulder.
1.5% less expensive
Chicago-Naperville-Elgin, IL-IN is 1.5% less expensive than Boulder, CO on BEA Regional Price Parities (overall RPP 103.6 vs 105.2). A $100,000 salary in Boulder buys about the same as $98,472 in Chicago-Naperville-Elgin; the largest component gap is rents.
- Overall RPP 105.2 (Boulder) vs 103.6 (Chicago-Naperville-Elgin)
- $100k in Boulder ≈ $98,472 purchasing power in Chicago-Naperville-Elgin
- Rents drives the gap (-45.0 RPP points)
RPP parity plate
Pair CO:IL 105.2→103.6
PHOTO-FINISH · CROSS-STATE · SPLIT-BUDGET · BOTH-ABOVE · PP-PAR
- PHOTO-FINISH Photo finish
- CROSS-STATE CO × IL
- SPLIT-BUDGET Split budget
- BOTH-ABOVE Both above 100
- PP-PAR PP near-par
Instrument codes from this pair's BEA Regional Price Parities (overall · goods · services · rents · national benchmark 100 · purchasing-power conversion), not a ranking or recommendation.
Boulder
105.2
Cost Index
Chicago-Naperville-Elgin
103.6
Cost Index
What This Comparison Actually Tells You
Boulder, CO and Chicago-Naperville-Elgin, IL-IN are a photo finish on overall price level, only 1.6 RPP points apart. A salary conversion is therefore a fine adjustment, not evidence of a fundamentally different cost regime.
Rents creates the largest separation: Chicago-Naperville-Elgin is 45.0 points lower. But goods and services move against the overall direction, so this is a split budget rather than a clean across-the-board winner.
Comparable population context is incomplete for this pair, so no market-scale explanation is inferred from the price indexes.
Both metros exceed the U.S. benchmark of 100. The choice is between two national premiums, so local wages need to clear the higher baseline in either market.
For a housing-sensitive move, validate the rent gap first: HUD Fair Market Rent and the actual unit size can overturn what the blended index implies. On the BEA ratio alone, $100,000 in Boulder corresponds to $98,472 in Chicago-Naperville-Elgin.
Category Breakdown
Goods
- Boulder
- 96.1
- Chicago-Naperville-Elgin
- 107.3
Diff +11.2 RPP
Services
- Boulder
- 82.7
Diff +0.8 RPP
Rents
- Boulder
- 157.0
- Chicago-Naperville-Elgin
- 112.0
Diff -45.0 RPP
| Category | Boulder | Chicago-Naperville-Elgin | Difference |
|---|---|---|---|
| Overall | 105.2 | 103.6 | -1.6 |
| Goods | 96.1 | 107.3 | +11.2 |
| Services | 82.7 | 83.6 | +0.8 |
| Rents | 157.0 | 112.0 | -45.0 |
Visual Comparison
Overall
Boulder 105.2
Chicago-Naperville-Elgin 103.6
Goods
Boulder 96.1
Chicago-Naperville-Elgin 107.3
Services
Boulder 82.7
Chicago-Naperville-Elgin 83.6
Rents
Boulder 157.0
Chicago-Naperville-Elgin 112.0
Vertical line = national average (100)
How the Price Gap Changed
Boulder and Chicago-Naperville-Elgin share 17 published annual releases from 2008 through 2024. Their overall gap narrowed, moving from 3.1 to 1.6 RPP points. Boulder remained the higher-index metro in the latest release.
Rents changed the most within this pair: its gap moved 23.3 points between the first and latest shared releases (21.7 to 45.0 points). This describes a relative price-index history, not a forecast or a household budget.
| Release Year | Boulder RPP | Chicago-Naperville-Elgin RPP | Relative Gap |
|---|---|---|---|
| 2008 | 108.5 | 105.4 | 3.1 points Boulder higher |
| 2012 | 107.5 | 105.1 | 2.4 points Boulder higher |
| 2016 | 105.6 | 103.8 | 1.8 points Boulder higher |
| 2020 | 101.7 | 104.5 | 2.8 points Chicago-Naperville-Elgin higher |
| 2024 | 105.2 | 103.6 | 1.6 points Boulder higher |
Annual BEA Regional Price Parity releases; a higher index means a higher price level relative to the national average of 100. Selected years shown from the full shared series.
Salary Equivalents
What a salary in Boulder would need to be in Chicago-Naperville-Elgin for the same purchasing power:
| In Boulder | In Chicago-Naperville-Elgin | Difference |
|---|---|---|
| $50,000 | $49,236 | $-764 |
| $75,000 | $73,854 | $-1,146 |
| $100,000 | $98,472 | $-1,528 |
| $150,000 | $147,709 | $-2,291 |
$ in Boulder = in Chicago-Naperville-Elgin
Same BEA Regional Price Parity ratio as the table above (105.2 → 103.6), computed live from your number, nothing is sent anywhere.
Frequently Asked Questions
Is Chicago-Naperville-Elgin more expensive than Boulder?
Chicago-Naperville-Elgin is 1.5% less expensive than Boulder. The overall cost index is 103.6 vs 105.2 (national average = 100).
What salary in Chicago-Naperville-Elgin equals $100K in Boulder?
A $100,000 salary in Boulder has the same purchasing power as $98,472 in Chicago-Naperville-Elgin. This is based on the BEA Regional Price Parity indexes.
How do rents compare between Boulder and Chicago-Naperville-Elgin?
Rents in Boulder are indexed at 157.0 while Chicago-Naperville-Elgin is at 112.0 (national average = 100). Boulder has higher rents.
Data sources
- BEA Regional Price Parities (RPP), the cost-of-living indices shown on this page
- U.S. Census Bureau, American Community Survey (ACS), gross-rent observations behind the rents component
- BLS Consumer Price Index (CPI), goods and services price relatives
- BLS Occupational Employment and Wage Statistics (OEWS), labor-driven services component
- HUD Fair Market Rents (FMR), 40th-percentile rent cross-reference
Every figure on PlainCost is rendered directly from BEA Regional Price Parity source data, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, our changelog, or report a data error. Data current as of 2026-08-11. Rankings measure the published cost-of-living index only; we don't recommend where to live or rate any metro's quality of life.