$120K in Idaho Falls = $117,241 in Lafayette
Your $120K salary in Idaho Falls (COL 87) has the same purchasing power as $117,241 in Lafayette (COL 85). Lafayette is cheaper — your money goes 2% further there.
Budget breakdown — $120K in both cities
What $120K actually buys you in each city after taxes and core expenses.
| Expense | Idaho Falls $120K | Lafayette $120K (same salary) |
|---|---|---|
| Monthly take-home | $6,575 | $6,725 |
| 1BR rent | $1,100 | $1,100 |
| Groceries | $365 | $361 |
| Transport | $35 | $42 |
| Utilities | $142 | $208 |
| Internet | $65 | $58 |
| Left after essentials | $4,868/month | $4,956/month |
Frequently asked questions
What is $120K in Idaho Falls equivalent to in Lafayette?
$120K in Idaho Falls (COL index 87) has the same purchasing power as $117,241 in Lafayette (COL index 85). That's 2% less than your current salary.
If I move from Idaho Falls to Lafayette keeping my $120K salary, will I be better off?
Yes. If you keep earning $120K after moving to Lafayette, you'd have $88 more per month after core expenses — because Lafayette is cheaper than Idaho Falls.
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: $120K × (85 ÷ 87) = $117,241. This adjusts for differences in housing, food, transport, and general cost of living.
Other salary amounts — Idaho Falls to Lafayette
Equivalency uses overall COL index ratio. Take-home uses simplified federal/state brackets. Zillow · BLS · Numbeo · Q1 2026 · For general guidance only