Side-by-side tax comparison between Connecticut (6.99% top rate, graduated) and South Dakota (no income tax). See which state lets you keep more at every salary level, and how cost of living changes the picture.
South Dakota has no state income tax, while Connecticut uses a graduated system with rates of 3-6.99%. On a $100K salary, this creates a state tax difference of $4,544/year that South Dakota residents simply don’t pay.
Connecticut’s graduated brackets mean the gap between these two states widens at higher salaries. At $200K, the state tax difference grows to $9,087/year, while at $50K it’s only $2,272.
South Dakota wins at 10 out of 10 salary levels tested. The advantage is consistent and significant across the income spectrum.
| Salary | Connecticut | South Dakota | Difference | Winner |
|---|---|---|---|---|
| $40K | $32,503 | $34,320 | +$1,817 | South Dakota |
| $50K | $40,083 | $42,355 | +$2,272 | South Dakota |
| $60K | $47,664 | $50,390 | +$2,726 | South Dakota |
| $75K | $58,130 | $61,538 | +$3,408 | South Dakota |
| $100K | $74,582 | $79,125 | +$4,544 | South Dakota |
| $120K | $87,743 | $93,195 | +$5,452 | South Dakota |
| $150K | $106,936 | $113,751 | +$6,815 | South Dakota |
| $200K | $139,800 | $148,887 | +$9,087 | South Dakota |
| $250K | $171,905 | $183,264 | +$11,359 | South Dakota |
| $300K | $201,698 | $215,329 | +$13,631 | South Dakota |
Take-home pay only tells part of the story. Connecticut has a cost of living index of 111 while South Dakota is at 92 (national average = 100).
This is a substantial difference. After adjusting for cost of living, $100K in Connecticut has purchasing power of $67,191 compared to $86,005 in South Dakota. South Dakota 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 $80,167 in Connecticut and $84,710 in South Dakota \u2014 a difference of $4,544. The gap remains similar regardless of filing status.
On paper, moving from Connecticut to South Dakota would save $4,544/year on a $100K salary, or $22,718 over 5 years. But relocation involves real costs: moving expenses, potentially buying/selling a home, changing jobs, and adjusting to a new community.
The $4,544/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.