Illinois Income Tax Calculator
Calculate your Illinois (IL) state income tax for 2026. Get an instant estimate based on official IL tax brackets.
Your Illinois Tax Estimate
Illinois Tax Brackets for 2026
Illinois has a flat 4.95% state income tax rate — the same rate applies to all income levels, regardless of how much you earn.
Tax brackets are estimates for 2026. Actual brackets may vary slightly due to inflation adjustments. Check the official Illinois Department of Revenue for the most current rates.
How Illinois Income Tax Works
Illinois uses a flat-rate tax system: every taxpayer pays the same percentage (4.95%) of their taxable income, regardless of how much they earn. The state calculates your taxable income by subtracting the standard deduction (or itemized deductions) from your gross income, then multiplies by 4.95%.
When you earn income in Illinois, your employer withholds both federal income tax (sent to the IRS) and IL state tax (sent to the Illinois Department of Revenue). At tax time, you file two separate returns: one federal (Form 1040) and one IL state return.
You can file Illinois state taxes through tax software (TurboTax, H&R Block, FreeTaxUSA), hire a local accountant, or file directly with the Illinois Department of Revenue. Most IL state returns are due April 15, the same as federal. Some states offer a 6-month extension (to October 15) if you also extend your federal return.
Example: Illinois Tax on $75,000
A single Illinois resident earning $75,000 in 2026 would pay approximately:
- Federal tax: ~$10,500 (24% marginal bracket, after deductions)
- IL state tax: $2,990 (calculated using the brackets above)
- FICA (Social Security + Medicare): $5,738 (7.65% on first $168,600)
- Total annual tax burden: ~$19,228
- Effective tax rate: 25.6% (combined federal + IL state)
Use the calculator above to get your personalized estimate. Adjust the income to see how raises, bonuses, or side income affect your IL tax.
Frequently Asked Questions
What is the Illinois state income tax rate for 2026?
Illinois uses a flat tax rate of 4.95% on all taxable income.
Does Illinois have a state income tax?
Yes, Illinois has a state income tax. The state taxes most types of income, including wages, salaries, self-employment income, and retirement distributions. Illinois brackets are flat at 4.95%.
How do I file Illinois state taxes?
You file Illinois state taxes separately from your federal return. Most residents use state tax software, an accountant, or file directly with the Illinois Department of Revenue. The state return is due April 15 (or April 30 for some states) — same as federal.
What deductions does Illinois allow?
Illinois allows the standard deduction (set by the state, not always the same as federal). Most states also allow itemized deductions, retirement income exclusions, and state-specific credits for education, retirement, and working families.
Is Illinois tax-friendly for retirees?
Illinois is moderately retiree-friendly. The 4.95% flat rate applies to retirement income. Social Security is not taxed at the state level. There is no special senior deduction, but the standard deduction is available to all filers.