Illinois State Income Tax Calculator
Calculate your Illinois state income tax liability for 2026
About Illinois State Income Tax
Tax Brackets & Rates (2026)
| Income Range | Tax Rate |
|---|---|
| Over $0 | 4.95% |
Deductions & Exemptions
- Personal Exemption: $2,425 per taxpayer
How Illinois State Income Tax Works
Illinois uses a flat tax rate of 4.95% on all taxable income. This means all income above deductions and exemptions is taxed at the same rate.
Tips for Illinois Taxpayers
- File your state return by the same deadline as federal taxes (typically April 15)
- Make estimated quarterly payments if you're self-employed or have significant investment income
- Keep detailed records of all income, deductions, and tax payments
- Consider contributions to tax-advantaged accounts like 401(k)s and IRAs to reduce taxable income