Side-by-side tax comparison between California (13.3% top rate, graduated) and Idaho (5.3% top rate, flat). See which state lets you keep more at every salary level, and how cost of living changes the picture.
California uses a graduated income tax (1-13.3%) while Idaho has a flat system (5.3% flat). On a $100K salary, California takes $8,645 in state and local taxes compared to Idaho’s $5,300 \u2014 a difference of $3,345.
Because California has graduated brackets while Idaho is flat, the gap between them changes at different income levels. California’s rates increase with income, so high earners feel the difference more acutely.
Idaho wins at 10 out of 10 salary levels tested. The advantage is consistent and significant across the income spectrum.
| Salary | California | Idaho | Difference | Winner |
|---|---|---|---|---|
| $40K | $30,862 | $32,200 | +$1,338 | Idaho |
| $50K | $38,033 | $39,705 | +$1,673 | Idaho |
| $60K | $45,203 | $47,210 | +$2,007 | Idaho |
| $75K | $55,054 | $57,563 | +$2,509 | Idaho |
| $100K | $70,480 | $73,825 | +$3,345 | Idaho |
| $120K | $82,821 | $86,835 | +$4,014 | Idaho |
| $150K | $100,784 | $105,801 | +$5,018 | Idaho |
| $200K | $131,597 | $138,287 | +$6,690 | Idaho |
| $250K | $161,652 | $170,014 | +$8,363 | Idaho |
| $300K | $189,394 | $199,429 | +$10,035 | Idaho |
Take-home pay only tells part of the story. California has a cost of living index of 142 while Idaho is at 95 (national average = 100).
This is a substantial difference. After adjusting for cost of living, $100K in California has purchasing power of $49,634 compared to $77,711 in Idaho. Idaho wins on both raw take-home and cost-adjusted purchasing power, making it the clear winner for a $100K earner.
For a single earner at $100K filing jointly, take-home becomes $76,065 in California and $79,410 in Idaho \u2014 a difference of $3,345. The gap remains similar regardless of filing status.
On paper, moving from California to Idaho would save $3,345/year on a $100K salary, or $16,725 over 5 years. But relocation involves real costs: moving expenses, potentially buying/selling a home, changing jobs, and adjusting to a new community.
The $3,345/year savings is meaningful but probably not enough to justify a move on its own. However, combined with other factors like career growth, lifestyle preferences, or family proximity, it could tip the scale.