$40K in Chicago = $37,383 in Naperville
Your $40K salary in Chicago (COL 107) has the same purchasing power as $37,383 in Naperville (COL 100). Naperville is cheaper — your money goes 7% further there.
Budget breakdown — $40K in both cities
What $40K actually buys you in each city after taxes and core expenses.
| Expense | Chicago $40K | Naperville $40K (same salary) |
|---|---|---|
| Monthly take-home | $2,565 | $2,562 |
| 1BR rent | $1,900 | $1,650 |
| Groceries | $388 | $380 |
| Transport | $105 | $72 |
| Utilities | $165 | $158 |
| Internet | $65 | $62 |
| Left after essentials | -$58/month | $240/month |
Frequently asked questions
What is $40K in Chicago equivalent to in Naperville?
$40K in Chicago (COL index 107) has the same purchasing power as $37,383 in Naperville (COL index 100). That's 7% less than your current salary.
If I move from Chicago to Naperville keeping my $40K salary, will I be better off?
Yes. If you keep earning $40K after moving to Naperville, you'd have $298 more per month after core expenses — because Naperville is cheaper than Chicago.
How is the salary equivalent calculated?
The equivalent salary is calculated by multiplying your current salary by the ratio of the two cities' overall cost of living indices: $40K × (100 ÷ 107) = $37,383. This adjusts for differences in housing, food, transport, and general cost of living.
Other salary amounts — Chicago to Naperville
Equivalency uses overall COL index ratio. Take-home uses simplified federal/state brackets. Zillow · BLS · Numbeo · Q1 2026 · For general guidance only