What is the illinois income tax calculator — federal + state tax?
In short
Illinois levies a flat 4.95% income tax on top of federal income tax and FICA. On a $75,000 income, a single filer in Illinois owes roughly $17,068 in total tax — about $8,341 federal, $2,990 Illinois state tax, and $5,738 FICA — leaving $57,932 take-home (a 22.8% effective rate).
This Illinois income tax calculator estimates your total 2024 tax burden. It applies federal income tax brackets, FICA (6.2% Social Security + 1.45% Medicare), and Illinois's state income tax (a flat 4.95% income tax), using the standard deduction or your itemized amount. Illinois applies the same 4.95% rate to every dollar of taxable income regardless of how much you earn.
How to use this calculator
- 1Enter your annual gross income.
- 2Choose your filing status (single, married, or head of household).
- 3Illinois is pre-selected as your state — change it to compare other states.
- 4Enter pre-tax deductions (401k, HSA) and any itemized deductions.
- 5Read your federal tax, state tax, FICA, total tax, and effective rate.
The formula
- AGI
- — Adjusted gross income — gross minus pre-tax deductions
- taxable income
- — AGI minus the standard or itemized deduction
- federal tax
- — Federal income tax from progressive 2024 brackets
- IL tax
- — Illinois state income tax — a flat 4.95% income tax
- FICA
- — Social Security (6.2%) + Medicare (1.45%) payroll taxes
Worked example
The scenario
Single filer earning $75,000/year in Illinois, taking the standard deduction, no pre-tax deductions.
The result
Federal income tax: ~$8,341. Illinois state tax: ~$2,990. FICA: ~$5,738. Total tax: ~$17,068 — leaving $57,932 take-home, an effective tax rate of 22.8%.
Common use cases
- Estimating your total tax bill before filing in Illinois
- Comparing Illinois's tax burden against other states before relocating
- Seeing how pre-tax 401(k) or HSA contributions lower your tax
- Understanding your effective vs. marginal tax rate
Limitations & assumptions
- Local/city income taxes are not included.
- State-specific credits, exemptions, and deductions are simplified; brackets approximate current law.
- Federal calculation uses 2024 brackets and the standard deduction unless you enter itemized amounts.
- This is an estimate, not tax advice; verify against your actual return.
Frequently asked questions
Disclaimer: KalkWise calculators are provided for general informational and educational purposes only and do not constitute financial, investment, tax, or legal advice. Results are estimates based on the figures you enter and the assumptions described above. Actual outcomes will vary. Consult a qualified professional before making financial decisions.