What is the Illinois income tax rate?

Illinois has a flat income tax rate of 5.0%. All taxable income is taxed at this same rate regardless of income level.

Does Illinois have a standard deduction?

Illinois does not offer a state standard deduction. Your state taxable income may be based on your federal adjusted gross income.

How is Illinois income tax calculated?

Illinois uses a flat tax system. After subtracting your standard deduction (if applicable), your remaining taxable income is taxed at a flat rate of 5.0%, then added to your federal tax and FICA obligations.

How do I calculate my total Illinois tax bill?

Your total tax includes federal income tax (10%–37%), Social Security (6.2% on the first $176,100), Medicare (1.45%), and Illinois state income tax. Use our free calculator above for an instant breakdown.

Illinois Income Tax Calculator 2026

Estimate your Illinois (IL) income tax for 2026. Illinois has a 5.0% flat state income tax. Enter your income below and click “Calculate Taxes” for an instant breakdown.

Note: No standard deduction; personal exemption $2,775

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Illinois Income Tax Overview

Illinois has a flat income tax rate of 5.0%. This means all taxable income is taxed at the same rate regardless of how much you earn.

Key Facts About Illinois Taxes

Illinois' flat 4.95% rate is constitutionally mandated — a 2020 ballot measure to switch to a progressive system was rejected by voters. The state offers a $2,775 personal exemption instead of a standard deduction.

Illinois has some of the highest property taxes in the nation (averaging 2.07% of home value), particularly in the Chicago suburbs, making total tax burden higher than the income tax rate alone suggests.

Frequently Asked Questions

What is the Illinois income tax rate?: Illinois has a flat income tax rate of 5.0%. All taxable income is taxed at this same rate regardless of income level.
Does Illinois have a standard deduction?: Illinois does not offer a state standard deduction. Your state taxable income may be based on your federal adjusted gross income.
How is Illinois income tax calculated?: Illinois uses a flat tax system. After subtracting your standard deduction (if applicable), your remaining taxable income is taxed at a flat rate of 5.0%, then added to your federal tax and FICA obligations.
How do I calculate my total Illinois tax bill?: Your total tax includes federal income tax (10%–37%), Social Security (6.2% on the first $176,100), Medicare (1.45%), and Illinois state income tax. Use our free calculator above for an instant breakdown.

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