Side-by-side tax comparison between Colorado (4.4% top rate, flat) and Montana (5.65% top rate, graduated). See which state lets you keep more at every salary level, and how cost of living changes the picture.
Colorado uses a flat income tax (4.4% flat) while Montana has a graduated system (4.7-5.65%). On a $100K salary, Colorado takes $4,400 in state and local taxes compared to Montana’s $3,673 \u2014 a difference of $728.
Because Colorado has flat brackets while Montana is graduated, the gap between them changes at different income levels. Colorado’s flat rate is predictable, while Montana’s graduated brackets may benefit lower earners but penalize higher incomes.
Montana wins at 10 out of 10 salary levels tested. The advantage exists but is modest across the income spectrum.
| Salary | Colorado | Montana | Difference | Winner |
|---|---|---|---|---|
| $40K | $32,560 | $32,851 | +$291 | Montana |
| $50K | $40,155 | $40,519 | +$364 | Montana |
| $60K | $47,750 | $48,187 | +$437 | Montana |
| $75K | $58,238 | $58,783 | +$546 | Montana |
| $100K | $74,725 | $75,453 | +$728 | Montana |
| $120K | $87,915 | $88,788 | +$873 | Montana |
| $150K | $107,151 | $108,242 | +$1,091 | Montana |
| $200K | $140,087 | $141,542 | +$1,455 | Montana |
| $250K | $172,264 | $174,083 | +$1,819 | Montana |
| $300K | $202,129 | $204,311 | +$2,183 | Montana |
Take-home pay only tells part of the story. Colorado has a cost of living index of 105 while Montana is at 97 (national average = 100).
The cost of living gap is moderate. After adjustment, $100K has purchasing power of $71,167 in Colorado vs $77,786 in Montana. The take-home winner also wins on purchasing power.
For a single earner at $100K filing jointly, take-home becomes $80,310 in Colorado and $81,038 in Montana \u2014 a difference of $728. The gap remains similar regardless of filing status.
On paper, moving from Colorado to Montana would save $728/year on a $100K salary, or $3,638 over 5 years. But relocation involves real costs: moving expenses, potentially buying/selling a home, changing jobs, and adjusting to a new community.
At $728/year, the tax difference alone likely isn’t worth relocating for. Other factors — job market, lifestyle, family — should drive the decision. The tax savings are a nice bonus if you’re already considering the move for other reasons.