Illinois charges 4.95% flat state income tax. Use the bonus tax calculator pre-loaded with Illinois rates.
Open Bonus Tax Calculator →When you receive a bonus in Illinois, your employer typically withholds at the federal supplemental rate of 22%, plus Illinois's flat 4.95%, and FICA at 7.65%. The combined withholding can make bonuses feel heavily taxed, though your actual liability may differ from withholding at year-end. This calculator shows both the withholding and the true tax on your bonus in Illinois.
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 bonus 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.