Overall
- Chicago-Naperville-Elgin
- 103.6
- Decatur
- 87.2
Diff -16.4 RPP
Chicago-Naperville-Elgin vs Decatur
Cost of living comparison based on BEA Regional Price Parities. Decatur is 15.8% less expensive than Chicago-Naperville-Elgin.
15.8% less expensive
Decatur, AL is 15.8% less expensive than Chicago-Naperville-Elgin, IL-IN on BEA Regional Price Parities (overall RPP 87.2 vs 103.6). A $100,000 salary in Chicago-Naperville-Elgin buys about the same as $84,186 in Decatur; the largest component gap is rents.
- Overall RPP 103.6 (Chicago-Naperville-Elgin) vs 87.2 (Decatur)
- $100k in Chicago-Naperville-Elgin ≈ $84,186 purchasing power in Decatur
- Rents drives the gap (-53.9 RPP points)
RPP parity plate
Pair IL:AL 103.6→87.2
TIER-GAP · CROSS-STATE · SPLIT-BUDGET · BENCH-CROSS · PP-STEEP
- TIER-GAP Clear tier gap
- CROSS-STATE IL × AL
- SPLIT-BUDGET Split budget
- 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.
Category Breakdown
Goods
- Chicago-Naperville-Elgin
- 107.3
- Decatur
- 96.4
Diff -10.9 RPP
Services
- Decatur
- 84.7
Diff +1.2 RPP
Rents
- Chicago-Naperville-Elgin
- 112.0
- Decatur
- 58.1
Diff -53.9 RPP
| Category | Chicago-Naperville-Elgin | Decatur | Difference |
|---|---|---|---|
| Overall | 103.6 | 87.2 | -16.4 |
| Goods | 107.3 | 96.4 | -10.9 |
| Services | 83.6 | 84.7 | +1.2 |
| Rents | 112.0 | 58.1 | -53.9 |
Visual Comparison
Overall
Chicago-Naperville-Elgin 103.6
Decatur 87.2
Goods
Chicago-Naperville-Elgin 107.3
Decatur 96.4
Services
Chicago-Naperville-Elgin 83.6
Decatur 84.7
Rents
Chicago-Naperville-Elgin 112.0
Decatur 58.1
Vertical line = national average (100)
What This Comparison Actually Tells You
Rents creates the largest separation: Decatur is 53.9 points lower. But services move against the overall direction, so this is a split budget rather than a clean across-the-board winner.
Chicago-Naperville-Elgin, IL-IN and Decatur, AL sit in clearly different price tiers, separated by 16.4 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 Decatur is below it. That makes the move a change of price regime, not merely a rank swap.
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 Chicago-Naperville-Elgin corresponds to $84,186 in Decatur.
Chicago-Naperville-Elgin
103.6
Cost Index
Decatur
87.2
Cost Index
Salary Equivalents
What a salary in Chicago-Naperville-Elgin would need to be in Decatur for the same purchasing power:
| In Chicago-Naperville-Elgin | In Decatur | Difference |
|---|---|---|
| $50,000 | $42,093 | $-7,907 |
| $75,000 | $63,139 | $-11,861 |
| $100,000 | $84,186 | $-15,814 |
| $150,000 | $126,278 | $-23,722 |
$ in Chicago-Naperville-Elgin = in Decatur
Same BEA Regional Price Parity ratio as the table above (103.6 → 87.2), computed live from your number, nothing is sent anywhere.
Frequently Asked Questions
Is Decatur more expensive than Chicago-Naperville-Elgin?
Decatur is 15.8% less expensive than Chicago-Naperville-Elgin. The overall cost index is 87.2 vs 103.6 (national average = 100).
What salary in Decatur equals $100K in Chicago-Naperville-Elgin?
A $100,000 salary in Chicago-Naperville-Elgin has the same purchasing power as $84,186 in Decatur. This is based on the BEA Regional Price Parity indexes.
How do rents compare between Chicago-Naperville-Elgin and Decatur?
Rents in Chicago-Naperville-Elgin are indexed at 112.0 while Decatur is at 58.1 (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.