How to Calculate Your Illinois Paycheck
Calculating your net paycheck in Illinois involves deducting Federal income tax, FICA taxes (Social Security and Medicare), and the Illinois state income tax from your gross pay. Unlike the federal government, which uses progressive tax brackets, Illinois simplifies state taxes by applying a flat percentage rate to all taxable income.
- Gross = Your total earnings before any deductions.
- IL Tax = Flat 4.95% rate applied to your taxable income (after standard exemptions).
- FICA = 7.65% total (6.2% Social Security + 1.45% Medicare).
- Fed Tax = Variable rate based on your federal tax bracket and filing status.
Disclaimer: This calculator provides an estimation. Actual withholdings may vary based on pre-tax deductions (like 401k or health insurance), specific W-4 allowances, and local municipality taxes.
Illinois allows a standard basic personal exemption ($2,425 for individuals, $4,850 for married couples filing jointly in 2024), which is subtracted from your annualized gross income before the 4.95% state tax rate is applied.
| Tax Type | Tax Rate | Notes |
|---|---|---|
| Illinois State Tax | 4.95% | Flat rate for all income levels. |
| Social Security | 6.20% | Capped at the annual wage base limit. |
| Medicare | 1.45% | No wage base limit. (Additional 0.9% for high earners). |
| Federal Income Tax | 10% to 37% | Progressive tax brackets based on annualized income. |
Frequently Asked Questions
Is the Illinois state income tax a flat rate?
Yes. Illinois uses a flat state income tax system. As of 2024, the state income tax rate is exactly 4.95% for all individual taxpayers, regardless of how much money they earn or their filing status.
Does Illinois have local city or county income taxes?
No. Unlike some other states, Illinois does not allow local municipalities (such as the City of Chicago or Cook County) to levy their own separate local income taxes on employee paychecks.
What is the standard deduction in Illinois?
Illinois does not have a "standard deduction" in the same way the federal government does. Instead, it offers a basic personal exemption. In 2024, the base exemption is $2,425 per person. This amount is subtracted from your gross income before the 4.95% flat tax is calculated.