$40K in Rockford = $39,512 in Springfield
Your $40K salary in Rockford (COL 82) has the same purchasing power as $39,512 in Springfield (COL 81). Springfield is cheaper — your money goes 1% further there.
Budget breakdown — $40K in both cities
What $40K actually buys you in each city after taxes and core expenses.
| Expense | Rockford $40K | Springfield $40K (same salary) |
|---|---|---|
| Monthly take-home | $2,562 | $2,562 |
| 1BR rent | $1,050 | $1,000 |
| Groceries | $357 | $357 |
| Transport | $50 | $48 |
| Utilities | $158 | $155 |
| Internet | $58 | $58 |
| Left after essentials | $889/month | $944/month |
Frequently asked questions
What is $40K in Rockford equivalent to in Springfield?
$40K in Rockford (COL index 82) has the same purchasing power as $39,512 in Springfield (COL index 81). That's 1% less than your current salary.
If I move from Rockford to Springfield keeping my $40K salary, will I be better off?
Yes. If you keep earning $40K after moving to Springfield, you'd have $55 more per month after core expenses — because Springfield is cheaper than Rockford.
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 × (81 ÷ 82) = $39,512. This adjusts for differences in housing, food, transport, and general cost of living.
Other salary amounts — Rockford to Springfield
Equivalency uses overall COL index ratio. Take-home uses simplified federal/state brackets. Zillow · BLS · Numbeo · Q1 2026 · For general guidance only