Illinois charges 4.95% flat state income tax. Use the stock option tax calculator pre-loaded with Illinois rates.
Open Stock Option Tax Calculator →Stock option exercises in Illinois are subject to a flat 4.95% state income tax on top of federal tax. For NSOs, the spread at exercise is ordinary income subject to both federal and Illinois state tax plus FICA. For ISOs, while there is no regular tax at exercise, the spread counts for AMT purposes and for Illinois state tax calculations. This calculator helps you plan the optimal time and amount to exercise given Illinois's tax rates.
Illinois levies a flat 4.95% state income tax on all taxable income regardless of how much you earn. This makes tax planning straightforward: for every additional dollar you earn, 4.95 cents goes to Illinois. Illinois does not impose local income taxes, so the 4.95% flat rate is the only state-level income tax you owe.
The table below shows what you actually keep at five salary levels in Illinois, accounting for federal tax, FICA, and Illinois's flat 4.95% state tax.
See how Illinois compares to other Midwest states. Each link takes you to the stock option tax calculator landing page for that state.
For a comprehensive breakdown of Illinois’s tax structure, salary comparisons, cost-of-living analysis, and more, visit the full Illinois take-home pay page.