CALCMONEY // ROTH CONVERSION // IL
Illinois residents pay 4.95% flat state tax on Roth conversions, on top of federal. A $100K conversion costs $26,950 upfront.
Open Full Calculator4.95% flat
27.0%
$26,950
$67,375
| Conversion Amount | Federal Tax | IL State Tax | Total Upfront |
|---|---|---|---|
| $100K (22% federal) | $22,000 | $4,950 | $26,950 |
| $250K (22% federal) | $55,000 | $12,375 | $67,375 |
| $500K (32% federal) | $160,000 | $24,750 | $184,750 |
| Conversion | Upfront Tax | Roth Value (20yr) | Traditional Net |
|---|---|---|---|
| $100K conversion | $26,950 | $386,968 | $263,139 |
| $250K conversion | $67,375 | $967,421 | $657,846 |
Roth advantage depends on future vs current tax rates. If your rate at 72 (RMD age) is higher than today, converting now wins. If lower, traditional may win. State tax treatment of withdrawals matters: Illinois exempts traditional IRA distributions, which reduces the Roth advantage.
Illinois taxes ordinary income at 4.95% flat. Roth conversions are treated as ordinary income, so a large conversion adds to your IL state tax bill in the year you convert. At the top state rate of 5.0%, a $250K conversion costs $12,375 in state tax alone.
Illinois exempts retirement income (401k, IRA, pension distributions) from state income tax. This changes the Roth calculus: if you convert now, you pay state tax; if you leave funds in a traditional IRA, future withdrawals may also be exempt. Run the numbers on whether a conversion still makes sense given this exemption. It often still does for federal tax reasons, but the state advantage of Roth narrows.