Side-by-side tax comparison between Idaho (5.8% top rate) and Washington (no income tax).
| Salary | Idaho | Washington | Difference | Winner |
|---|---|---|---|---|
| $50K | $40,123 | $42,298 | +$2,175 | Washington |
| $75K | $58,040 | $61,303 | +$3,263 | Washington |
| $100K | $74,540 | $78,890 | +$4,350 | Washington |
| $150K | $106,921 | $113,446 | +$6,525 | Washington |
| $200K | $140,403 | $149,103 | +$8,700 | Washington |
Washington offers higher take-home pay at every salary level. With no state income tax, Washington gives you a significant advantage over Idaho's 5.8% top rate. At $100K, the difference is $4,350/year — that’s $363/month.
However, cost of living matters. Idaho has a cost index of 95 while Washington is at 110. After adjusting for cost of living, the gap narrows significantly.