$40K in Topeka = $43,500 in Idaho Falls
Your $40K salary in Topeka (COL 80) has the same purchasing power as $43,500 in Idaho Falls (COL 87). Idaho Falls is more expensive — you'd need 9% more to maintain the same lifestyle.
Budget breakdown — $40K in both cities
What $40K actually buys you in each city after taxes and core expenses.
| Expense | Topeka $40K | Idaho Falls $40K (same salary) |
|---|---|---|
| Monthly take-home | $2,538 | $2,535 |
| 1BR rent | $940 | $1,100 |
| Groceries | $350 | $365 |
| Transport | $40 | $35 |
| Utilities | $150 | $142 |
| Internet | $55 | $65 |
| Left after essentials | $1,003/month | $828/month |
Frequently asked questions
What is $40K in Topeka equivalent to in Idaho Falls?
$40K in Topeka (COL index 80) has the same purchasing power as $43,500 in Idaho Falls (COL index 87). That's 9% more than your current salary.
If I move from Topeka to Idaho Falls keeping my $40K salary, will I be better off?
Not necessarily. Core expenses in Idaho Falls are higher, so on the same $40K salary you'd have $175 less per month. You'd need to earn $43,500 to maintain the same standard of living.
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 × (87 ÷ 80) = $43,500. This adjusts for differences in housing, food, transport, and general cost of living.
Other salary amounts — Topeka to Idaho Falls
Equivalency uses overall COL index ratio. Take-home uses simplified federal/state brackets. Zillow · BLS · Numbeo · Q1 2026 · For general guidance only