Illinois state tax at a glance
Flat 4.95% state income tax
Illinois uses a flat 4.95% income tax rate on all income
Advanced Mode
Enter required values to see results
AI InsightsSmart
Calculate to generate insights.
State tax summary
| Tax type | Rate / details |
|---|---|
| State income tax | Flat 4.95% |
How Illinois paycheck taxes work
Illinois uses a flat 4.95% state income tax on all taxable income. There is no standard deduction at the state level for the flat tax. Your employer withholds Illinois tax based on your IL-W-4 and the state's withholding tables.