Illinois Paycheck Calculator 2026
State
Illinois (IL)
Tax Type
Flat Rate Tax
State Tax Rate
Flat 4.95%
Illinois State Income Tax Overview
Illinois imposes a flat state income tax rate of 4.95% on all taxable income. This means every dollar of your taxable income is taxed at the same rate, regardless of how much you earn.
How Illinois Taxes Work in 2026
Illinois levies a flat state income tax rate of 4.95% on all taxable income. A flat tax means every taxpayer pays the same percentage, regardless of income level, which simplifies tax filing. Illinois offers a standard deduction of $2,770 for single filers and $5,540 for married filing jointly. This deduction reduces your taxable income before the 4.95% rate is applied. In addition to the 4.95% state income tax, Illinois residents also pay federal income tax (10% to 37% based on income) and FICA taxes (6.2% Social Security + 1.45% Medicare).
Illinois Flat Tax Rate
Illinois applies a flat income tax rate of 4.95% on all taxable income, regardless of filing status or income level.
Standard deduction: $2,770 (single) / $5,540 (married filing jointly)