Can I Afford to Live in Boulder vs Koh Samui on $40K?

Here's how a $40K/year salary plays out in both cities after taxes, rent, and core living expenses — based on Q1 2026 data.

Boulder, CO
$2,582/mo take-home
Rent: $2,300/mo (89% of take-home)
Difficult
Koh Samui, TH
$2,728/mo take-home
Rent: $620/mo (23% of take-home)
Comfortable

Monthly budget breakdown

Boulder
CO
Koh Samui
TH
Monthly take-home (est.)
$2,582
$2,728Best ✓
1BR rent
$2,300
$620Best ✓
Groceries (est.)
$414
$380Best ✓
Transport (est.)
$80Best ✓
$150
Utilities
$138
$70Best ✓
Internet
$68
$28Best ✓
Left after essentials
-$418/month
$1,480/month
Koh Samui (Surat Thani Province) has no state income tax, boosting take-home vs Boulder (CO rate: 4.4%).

Frequently asked questions

Is $40K a good salary in Boulder?

At $40K/year in Boulder, your estimated monthly take-home is $2,582. With 1BR rent around $2,300/month, rent takes up 89% of your take-home. That's considered difficult.

Is $40K a good salary in Koh Samui?

At $40K/year in Koh Samui, your estimated monthly take-home is $2,728. With 1BR rent around $620/month, rent takes up 23% of your take-home. That's considered comfortable.

Which city is more affordable on a $40K salary?

Koh Samui leaves you with more money after core expenses — $1,480/month vs $-418/month in Boulder.

Can I afford to live alone in Boulder on $40K?

It's tight. Rent in Boulder would take 89% of your $40K take-home pay. You may need to find roommates or look at studios to stay within the 30% rule.

Compare other salary bands — Boulder vs Koh Samui

$50K$60K$75K$80K$100K$120K$150K

See the full cost-of-living comparison

Rent, groceries, taxes, transportation, and more — side by side.

Full comparison

Take-home estimates use simplified federal/state brackets and do not account for pre-tax deductions, 401(k), or local taxes. Data: Zillow, BLS, Numbeo · Q1 2026 · For general guidance only