Tax Bracket for Illinois (2026)
Last updated: January 15, 2026
Illinois (IL) Key Facts
Tax Structure
Flat rate
Top Marginal Rate
4.95%
Number of Brackets
1
Tax Year
2,026
How This Calculator Works in Illinois
This calculator shows which Illinois tax bracket your income falls into. Enter your income and filing status to see marginal and effective rates.
Illinois Overview
Illinois levies a flat income tax rate of 4.95% on all taxable income. Unlike progressive states with multiple brackets, every dollar earned in Illinois is taxed at the same rate, making calculations predictable and straightforward.
How Illinois Compares
Illinois's top rate of 4.95% compares to Indiana at 3.05% and Wisconsin at 7.65%. Comparing effective rates is more meaningful than top rates alone.
| State | Top Rate | Notes |
|---|---|---|
| Indiana | 3.05% | Indiana has an income tax rate of 3.05%. |
| Wisconsin | 7.65% | Wisconsin has an income tax rate of 7.65%. |
| Missouri | 4.8% | Missouri has an income tax rate of 4.8%. |
Illinois's income tax rate of 4.95% compares to a national average of approximately 5.04%. This is below the national average.
Tips for Illinois Residents
- 1Illinois uses a flat income tax rate of 4.95%, meaning all taxable income is taxed at the same rate regardless of how much you earn.
- 2With a flat tax, your marginal rate and effective state rate are the same—4.95%.
- 3Federal brackets still apply progressively on top of Illinois's flat 4.95% rate.
- 4Pre-tax retirement contributions reduce both your federal bracket and the income subject to Illinois's flat 4.95%.
- 5Illinois's flat 4.95% is below the national average of about 5%, making withholding calculations straightforward.