Overall
- Rapid City
- 89.2
- Chicago-Naperville-Elgin
- 103.6
Diff +14.4 RPP
Rapid City vs Chicago-Naperville-Elgin
Cost of living comparison based on BEA Regional Price Parities. Chicago-Naperville-Elgin is 16.2% more expensive than Rapid City.
16.2% more expensive
Chicago-Naperville-Elgin, IL-IN is 16.2% more expensive than Rapid City, SD on BEA Regional Price Parities (overall RPP 103.6 vs 89.2). A $100,000 salary in Rapid City buys about the same as $116,190 in Chicago-Naperville-Elgin; the largest component gap is rents.
- Overall RPP 89.2 (Rapid City) vs 103.6 (Chicago-Naperville-Elgin)
- $100k in Rapid City ≈ $116,190 purchasing power in Chicago-Naperville-Elgin
- Rents drives the gap (+39.5 RPP points)
RPP parity plate
Pair SD:IL 89.2→103.6
TIER-GAP · CROSS-STATE · RENT-LED · BENCH-CROSS · PP-STEEP
- TIER-GAP Clear tier gap
- CROSS-STATE SD × IL
- RENT-LED Rent-led gap
- BENCH-CROSS Benchmark cross
- PP-STEEP Steep PP convert
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.
Salary Equivalents
What a salary in Rapid City would need to be in Chicago-Naperville-Elgin for the same purchasing power:
| In Rapid City | In Chicago-Naperville-Elgin | Difference |
|---|---|---|
| $50,000 | $58,095 | +$8,095 |
| $75,000 | $87,142 | +$12,142 |
| $100,000 | $116,190 | +$16,190 |
| $150,000 | $174,285 | +$24,285 |
$ in Rapid City = in Chicago-Naperville-Elgin
Same BEA Regional Price Parity ratio as the table above (89.2 → 103.6), computed live from your number, nothing is sent anywhere.
What This Comparison Actually Tells You
Rapid City, SD and Chicago-Naperville-Elgin, IL-IN sit in clearly different price tiers, separated by 14.4 RPP points. At this distance, treating the same nominal salary as equivalent would materially change purchasing power.
This route crosses the national benchmark: Chicago-Naperville-Elgin is above 100 while Rapid City is below it. That makes the move a change of price regime, not merely a rank swap.
Rents leads the difference, with Chicago-Naperville-Elgin 39.5 points higher than Rapid City. Goods, services, and rents all point in the same broad direction, making the headline comparison more transferable across household types.
Comparable population context is incomplete for this pair, so no market-scale explanation is inferred from the price indexes.
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 Rapid City corresponds to $116,190 in Chicago-Naperville-Elgin.
Category Breakdown
Goods
- Rapid City
- 95.5
- Chicago-Naperville-Elgin
- 107.3
Diff +11.8 RPP
Services
- Rapid City
- 79.1
Diff +4.5 RPP
Rents
- Rapid City
- 72.6
- Chicago-Naperville-Elgin
- 112.0
Diff +39.5 RPP
| Category | Rapid City | Chicago-Naperville-Elgin | Difference |
|---|---|---|---|
| Overall | 89.2 | 103.6 | +14.4 |
| Goods | 95.5 | 107.3 | +11.8 |
| Services | 79.1 | 83.6 | +4.5 |
| Rents | 72.6 | 112.0 | +39.5 |
Visual Comparison
Overall
Rapid City 89.2
Chicago-Naperville-Elgin 103.6
Goods
Rapid City 95.5
Chicago-Naperville-Elgin 107.3
Services
Rapid City 79.1
Chicago-Naperville-Elgin 83.6
Rents
Rapid City 72.6
Chicago-Naperville-Elgin 112.0
Vertical line = national average (100)
Rapid City
89.2
Cost Index
Chicago-Naperville-Elgin
103.6
Cost Index
Frequently Asked Questions
Is Chicago-Naperville-Elgin more expensive than Rapid City?
Chicago-Naperville-Elgin is 16.2% more expensive than Rapid City. The overall cost index is 103.6 vs 89.2 (national average = 100).
What salary in Chicago-Naperville-Elgin equals $100K in Rapid City?
A $100,000 salary in Rapid City has the same purchasing power as $116,190 in Chicago-Naperville-Elgin. This is based on the BEA Regional Price Parity indexes.
How do rents compare between Rapid City and Chicago-Naperville-Elgin?
Rents in Rapid City are indexed at 72.6 while Chicago-Naperville-Elgin is at 112.0 (national average = 100). Chicago-Naperville-Elgin 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.