Illinois Income Tax Calculator
Enter your annual gross income to estimate your Illinois state income tax.
- Free
- No sign-up
- Updated for 2026
Enter your income to estimate the state tax.
Worked example
With these example inputs:
- Annual gross income$80,000
Illinois income tax: $3,819
- Gross income$80,000
- Income tax$3,819
- Take-home pay$76,181
- Marginal rate5.0%
- Effective rate4.8%
Frequently asked questions
How does Illinois tax income?
Illinois charges a single flat rate of 4.95% on taxable income. On $80,000 with the personal exemption, the estimated state tax is around $3,823.
Why is there no bracket structure?
Illinois taxes all income at the same percentage rather than rising bands. A personal exemption reduces taxable income before the flat rate applies.