Illinois Income Tax Calculator

How to Use This Illinois Income Tax Calculator

This Illinois income tax calculator estimates your annual state and federal tax liability for 2025 and 2026. Enter your gross wages, filing status, and any pre-tax deductions above. Illinois applies a flat 4.95% rate to taxable income after subtracting the personal exemption ($2,925 per person in 2026) — no brackets, no phase-outs, no complexity.

This tool focuses on your annual tax picture — useful for tax planning, comparing job offers in different states, or estimating what you owe at filing time. For a per-paycheck breakdown, use the Illinois paycheck calculator; to compare Illinois with other states, use the general income tax calculator.

How Illinois's Flat 4.95% Tax Rate Works

Illinois is one of a handful of states that uses a flat income tax — a single rate applied to all taxable income regardless of how much you earn. The rate has been 4.95% since 2017, when it increased from 3.75% following a temporary rate expiration. There are no brackets, so earning more never changes the rate applied to your income.

Illinois voters rejected a 2020 constitutional amendment that would have allowed graduated brackets (rates up to 7.99%), preserving the flat tax. The rate applies to:

• W-2 wages and salaries — including bonuses and overtime.
• Self-employment income — net earnings after business deductions.
• Pension and retirement income — but Illinois entirely exempts most retirement income including Social Security, pension distributions from Illinois public plans, and IRA/401(k) distributions for residents age 65 or older (under certain conditions).
• Capital gains — taxed as ordinary income at 4.95%; no preferential capital gains rate at the state level.

Illinois Personal Exemption and No Standard Deduction

Illinois has no standard deduction. Instead, it provides a personal exemption of $2,925 per person in 2026 (indexed annually for inflation; $2,850 in 2025). This is the only income adjustment allowed at the state level before applying the 4.95% rate, aside from specific Illinois-only add-backs and subtractions.

For a single filer with $75,000 in gross income in 2026, the Illinois calculation is:

1. Gross income: $75,000
2. Subtract personal exemption: $75,000 − $2,925 = $72,075 (Illinois taxable income)
3. Apply flat rate: $72,075 × 4.95% = $3,568 in Illinois state income tax

Illinois also allows subtractions for certain retirement income, military pay, and federally taxed Social Security benefits — these are handled within the calculator when applicable. Illinois does recognize 401(k) and traditional IRA pre-tax contributions, reducing Illinois taxable income in the same way as federal taxable income.

FICA Taxes — Social Security and Medicare

FICA taxes are federal and apply to every Illinois paycheck:

• Social Security: 6.2% on wages up to $176,100 (2025) or $184,500 (2026). No further withholding once you hit the wage base.
• Medicare: 1.45% on all wages with no cap.
• Additional Medicare: 0.9% on wages above $200,000 (single) or $250,000 (married jointly) — employee only, no employer match.

Step-by-Step Example — $70,000 Illinois Single Filer (2026)

Here is a full tax calculation for a single Illinois resident earning $70,000 in gross wages in 2026, taking the standard deduction:

1. Gross wages: $70,000
2. Federal standard deduction: −$16,100 → federal taxable income: $53,900
3. Federal income tax (10% + 12% + 22% brackets): ≈ $6,570
4. FICA: $70,000 × 7.65% = $5,355
5. Illinois personal exemption: −$2,925 → IL taxable income: $67,075
6. Illinois income tax: $67,075 × 4.95% = $3,320
7. Total taxes: $6,570 + $5,355 + $3,320 = $15,245
8. Annual net income: $70,000 − $15,245 = $54,755

How to Reduce Your Illinois Annual Tax Liability

Illinois offers fewer deductions than the federal system, but pre-tax federal deductions also reduce your Illinois taxable income:

• Maximize traditional 401(k) contributions — the 2026 limit is $23,500 ($31,000 if 50+). At a combined 4.95% IL + 22% federal = 26.95% marginal rate, every $1,000 contributed saves $269.50 in taxes.
• Contribute to an HSA — $4,300 (self-only) or $8,550 (family) in 2026. Reduces both federal and Illinois taxable income.
• Illinois 529 College Savings Plan — Illinois taxpayers who contribute to the Bright Start or College Illinois 529 plans can deduct contributions from Illinois taxable income (up to $10,000 single / $20,000 joint per year).
• Illinois retirement income exemption — if you are over 65 and receive pension income from certain sources (including Social Security), that income may be exempt from Illinois tax even though it is federally taxable.
• Dependent Care FSA — up to $5,000 of childcare expenses paid with pre-tax dollars, reducing both federal and Illinois taxable income.

Retirement Income and Illinois Taxes

Illinois is one of the most retirement-friendly states in the countryfor income tax purposes. Despite the 4.95% flat rate on wages, Illinois exempts virtually all retirement income:

• Social Security benefits: Fully exempt from Illinois income tax, regardless of how much you receive or what your other income is. A retiree receiving $30,000 per year in Social Security owes $0 in Illinois state tax on that income.
• 401(k) and 403(b) distributions: Fully exempt from Illinois income tax. Withdrawals from traditional 401(k) and 403(b) plans — which were pre-tax when contributed — are not taxed again by Illinois at distribution.
• IRA withdrawals: Fully exempt from Illinois income tax. Both traditional IRA distributions (which are federally taxable) and Roth IRA distributions are exempt from Illinois tax.
• Pension income: Fully exempt — both Illinois public employee pensions (state, county, and municipal government employees) and private employer pension plans qualify for the exemption.
• Railroad Retirement benefits: Fully exempt from Illinois income tax.
• Military retirement pay: Fully exempt from Illinois income tax.

The practical impact is significant: an Illinois retiree with $50,000 in Social Security, $30,000 in IRA distributions, and $20,000 in pension income owes $0 in Illinois state income tax on all $100,000. This makes Illinois unusually attractive for retirees despite the 4.95% working-age rate — the effective state tax rate in retirement drops to zero for most retirees. Compare this to states like Hawaii (Social Security fully taxed, pensions mostly taxed) or Idaho (Social Security and 401(k) distributions taxable, limited deduction only for those 65+).

Illinois Tax Credits and Deductions

Illinois offers limited but meaningful state-specific credits and deductions that can reduce annual tax liability:

• Illinois Earned Income Tax Credit (EITC): Illinois provides a state EITC equal to 20% of the federal EITC — one of the more generous state EITC matches. The credit is refundable if it exceeds Illinois tax owed. For a qualifying family receiving a $4,000 federal EITC, the Illinois credit adds $800 directly to their refund (or reduces Illinois tax owed by $800).
• Illinois Property Tax Credit: Illinois residents who pay property tax on their primary residence can claim a credit equal to 5% of property taxes paid, up to the amount of their Illinois income tax liability. If you pay $6,000 in Cook County property tax, you may claim up to $300 as a direct credit against Illinois income tax owed.
• K-12 Education Expense Credit: Parents of K-12 students may claim a credit of 25% of qualified education expenses up to a maximum credit of $750 per family. Qualifying expenses include textbooks, lab fees, and school supplies — not tuition for private schools.
• Illinois Bright Start and College Illinois 529 Deduction: Contributions to Illinois-sponsored 529 plans are deductible from Illinois taxable income up to $10,000 per year for single filers and $20,000 for married filing jointly. At 4.95%, the full $10,000 single deduction saves $495 in Illinois state tax annually. Non-Illinois 529 plans do not qualify for the Illinois deduction.
• Personal Exemption Credit: Illinois does not use a standard deduction; instead, each taxpayer and dependent receives a $2,925 personal exemption (2026), which reduces Illinois taxable income before the 4.95% rate applies.

Illinois Form IL-1040 is the state individual income tax return. The filing deadline is April 15 (same as federal), with an automatic six-month extension to October 15. An extension to file does not extend the time to pay — interest accrues on unpaid balances after April 15.

Tax Disclaimer

This calculator provides estimates for informational purposes only. It is not tax advice. Illinois tax rates, personal exemption amounts, and retirement income rules can change each year. Federal brackets, FICA wage bases, and standard deduction amounts also change annually. Results reflect 2025 and 2026 tax-year parameters. Consult a qualified tax professional or CPA for guidance on your specific situation.