Cost of Living in Illinois (IL)
Compare costs across 8 Illinois cities. From home services to salaries, see how IL stacks up against the national average.
8
Cities
93
Avg Cost Index
$61K
Avg Income
Direct Answer
Illinois's average cost index is 93, which is below the national baseline of 100. Decatur is the most affordable tracked city in IL at index 78, while Naperville is the most expensive at index 118.
The gap between the cheapest and most expensive tracked cities is 40 index points, so state-level averages should be used as a map, not a final budget.
State cost overviewBLS, Census, HUD inputsLast verified May 2026
Illinois Highlights: Most affordable city: Decatur (index 78). Most expensive: Naperville (index 118). The gap between cheapest and most expensive is 40 index points.
What Drives the Statewide Cost Picture?
Average index
93/100
Illinois is below the national cost baseline across tracked cities.
Cheapest city
Decatur
Decatur has a cost index of 78.
Most expensive
Naperville
Naperville has a cost index of 118.
Income average
$61K
Average median household income across 8 tracked IL cities.
Cheapest and Most Expensive Cities in Illinois
| City | Population | Cost Index | Median Income | Tier |
|---|---|---|---|---|
| Chicago | 2.7M | 107 | $62K | major |
| Joliet | 150K | 96 | $66K | mid |
| Naperville | 150K | 118 | $126K | small |
| Rockford | 149K | 84 | $40K | mid |
| Springfield | 114K | 87 | $53K | small |
| Champaign | 88K | 86 | $40K | small |
| Bloomington | 78K | 90 | $62K | small |
| Decatur | 71K | 78 | $37K | small |
Illinois State Taxes (2026)
Headline tax rates that affect your real take-home pay and total cost of living in Illinois.
State Income Tax
4.95%
flat system
Combined Sales Tax
8.81%
6.25% state + 2.56% avg local
Property Tax (Effective)
2.27%
~$6,810/yr on a $300K home
Income tax: Illinois uses a flat income tax at 4.95%. Estate tax applies at the state level. Estimate your take-home pay
State Planning Checklist
- Start with Decatur if the priority is lowest recurring cost inside Illinois.
- Compare Naperville against salary and tax advantages before assuming the higher-cost city is worse.
- Use city pages for rent, salary, insurance, and local service costs before making a relocation decision.