Illinois Take-Home Pay Calculator 2025: Federal + IL Flat State Tax

Illinois flat rate and what it covers

The Illinois Individual Income Tax is a flat 4.95 percent of taxable income. Taxable income is computed by starting from federal Adjusted Gross Income (AGI), making a few Illinois-specific additions and subtractions (typically small for wage earners), and applying any allowed credits at the state level.

The Illinois Personal Exemption was $2,425 per filer in 2024 but is phased out for higher incomes; for most professional salaries the exemption is small or zero. The Illinois Earned Income Tax Credit is available for lower-income filers (those eligible for the federal EITC). The Property Tax Credit allows residents to credit 5 percent of property taxes paid on their primary residence against state income tax (capped at fairly low levels).

The 2020 graduated-tax ballot defeat

In November 2020, Illinois voters considered a constitutional amendment to replace the flat tax with graduated brackets (the so-called Fair Tax). The amendment would have introduced rates from 4.75 percent for low incomes up to 7.99 percent for incomes above $250,000 single ($500,000 married). The measure was defeated 53 to 47 percent, leaving Illinois with the flat 4.95 percent structure indefinitely.

The defeat reflected concerns about both the proposed rates and Illinois's broader fiscal management. Illinois has the worst public pension funding situation among US states (Illinois pension liabilities exceed $130 billion in unfunded actuarial accrued liability) and persistent budget pressures that voters worried graduated rates would not solve.

Property tax: the much larger Illinois burden

Property tax in Illinois averages 2.05 percent of home value annually statewide, the second-highest in the US. Chicago and suburban Cook County average 2.5 percent or higher; some suburbs (Naperville, Hinsdale, Glencoe) charge 3.0 to 3.5 percent on certain commercial properties.

For a $400,000 home in suburban Chicago, expect $9,000 to $12,000 of annual property tax. For a $600,000 home in a higher-tax suburb, $15,000 to $18,000. These are among the highest in the US in absolute dollar terms.

Property tax is federally deductible up to the $10,000 SALT cap. For most Illinois homeowners, the SALT cap means much of property tax provides no federal deduction. Illinois itself offers a 5 percent state credit for primary-residence property tax paid, capped at fairly low levels (effectively a few hundred dollars annual maximum for most homeowners).

Cook County vs collar counties

Property tax rates and assessment practices differ meaningfully between Cook County (Chicago and inner suburbs) and the surrounding collar counties (DuPage, Lake, Will, Kane, McHenry). Cook County has historically had higher commercial property assessment rates than residential, which can shift property tax burdens significantly when commercial valuations are reassessed.

The collar counties generally have lower property tax rates but higher home values, so absolute tax bills are similar in many cases. Total housing-related tax burdens (mortgage + property tax + insurance + utilities) are roughly comparable across the Chicago metro for homes of similar size and quality.

Income tax credits and additions in Illinois

Illinois conforms closely to federal income definitions for wage earners. The main state-level adjustments are:

• Personal exemption: $2,425 (phasing out for higher incomes)
• Property Tax Credit: 5 percent of primary-residence property tax paid (capped)
• Earned Income Tax Credit: 20 percent of federal EITC (one of the more generous state EITCs)
• K-12 Education Expense Credit: up to $750 for K-12 education expenses
• 529 Plan contribution deduction: contributions to Illinois 529 plans (Bright Start, Bright Directions) are deductible from Illinois taxable income up to $10,000 single, $20,000 married joint

The 529 contribution deduction is particularly valuable: a $10,000 contribution at 4.95 percent saves $495 in Illinois state tax. Combined with federal-tax-free growth and qualified withdrawals, Illinois 529 plans are a high-return savings vehicle for college funding.

What this calculator does not include

Illinois personal exemption (small, around $120 of tax saving at 4.95 percent). Illinois Property Tax Credit (5 percent of primary-residence property tax, capped). Illinois EITC for lower-income filers. K-12 Education Expense Credit (up to $750). 529 plan contribution deduction (up to $10,000 single, $20,000 married joint). Property tax (high in Illinois, averaging 2.05 percent of home value statewide and 2.5 to 3.0 percent in Chicago suburbs). Cook County and collar county property tax differences. Federal SALT cap impact. Illinois corporate income tax (7 percent, plus 1.5 percent replacement tax, for C-corps; not relevant for wage income). For precise Illinois returns, use the IL-1040 form or full-featured tax software; this calculator covers the wage-income paycheck case at the flat state rate.