Illinois vs South Dakota:
Take-Home Pay Comparison
Side-by-side tax comparison between Illinois (4.95% top rate, flat) 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.
Tax Structure: Illinois vs South Dakota
South Dakota has no state income tax, while Illinois uses a flat system with rates of 4.95% flat. On a $100K salary, this creates a state tax difference of $4,950/year that South Dakota residents simply don’t pay.
Illinois’s flat 4.95% rate means the gap scales linearly with income. At $200K, you’d save $9,900 by being in South Dakota instead.
Take-Home at Every Salary Level
South Dakota wins at 10 out of 10 salary levels tested. The advantage is consistent and significant across the income spectrum.
| Salary | Illinois | South Dakota | Difference | Winner |
|---|---|---|---|---|
| $40K | $32,340 | $34,320 | +$1,980 | South Dakota |
| $50K | $39,880 | $42,355 | +$2,475 | South Dakota |
| $60K | $47,420 | $50,390 | +$2,970 | South Dakota |
| $75K | $57,825 | $61,538 | +$3,713 | South Dakota |
| $100K | $74,175 | $79,125 | +$4,950 | South Dakota |
| $120K | $87,255 | $93,195 | +$5,940 | South Dakota |
| $150K | $106,326 | $113,751 | +$7,425 | South Dakota |
| $200K | $138,987 | $148,887 | +$9,900 | South Dakota |
| $250K | $170,889 | $183,264 | +$12,375 | South Dakota |
| $300K | $200,479 | $215,329 | +$14,850 | South Dakota |
Cost of Living: Illinois (93) vs South Dakota (92)
Take-home pay only tells part of the story. Illinois has a cost of living index of 93 while South Dakota is at 92 (national average = 100).
With similar costs of living (93 vs 92), the tax difference is the primary factor. What you see in raw take-home pay is essentially what you get in purchasing power: $79,758 in Illinois vs $86,005 in South Dakota.
Married Filing Jointly: How It Changes the Comparison
For a single earner at $100K filing jointly, take-home becomes $79,760 in Illinois and $84,710 in South Dakota \u2014 a difference of $4,950. The gap remains similar regardless of filing status.
Should You Move from Illinois to South Dakota?
On paper, moving from Illinois to South Dakota would save $4,950/year on a $100K salary, or $24,750 over 5 years. But relocation involves real costs: moving expenses, potentially buying/selling a home, changing jobs, and adjusting to a new community.
The $4,950/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.