$40K in Koh Samui = $77,600 in Madison
Your $40K salary in Koh Samui (COL 50) has the same purchasing power as $77,600 in Madison (COL 97). Madison is more expensive — you'd need 94% 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 | Koh Samui $40K | Madison $40K (same salary) |
|---|---|---|
| Monthly take-home | $2,728 | $2,472 |
| 1BR rent | $620 | $1,650 |
| Groceries | $380 | $384 |
| Transport | $150 | $62 |
| Utilities | $70 | $162 |
| Internet | $28 | $63 |
| Left after essentials | $1,480/month | $151/month |
Frequently asked questions
What is $40K in Koh Samui equivalent to in Madison?
$40K in Koh Samui (COL index 50) has the same purchasing power as $77,600 in Madison (COL index 97). That's 94% more than your current salary.
If I move from Koh Samui to Madison keeping my $40K salary, will I be better off?
Not necessarily. Core expenses in Madison are higher, so on the same $40K salary you'd have $1,329 less per month. You'd need to earn $77,600 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 × (97 ÷ 50) = $77,600. This adjusts for differences in housing, food, transport, and general cost of living.
Other salary amounts — Koh Samui to Madison
Equivalency uses overall COL index ratio. Take-home uses simplified federal/state brackets. Zillow · BLS · Numbeo · Q1 2026 · For general guidance only