Capital Gains Calculator

Illinois Capital Gains Tax (2026)

By Nathan Hays · Updated July 26, 2026

Illinois taxes capital gains as ordinary income at a flat 4.95% rate. Run your own numbers with the free capital gains tax calculator, which estimates federal, NIIT, and Illinois tax together.

In short: federal long-term rates of 0%, 15%, or 20% apply everywhere. Illinois adds state tax on top, at up to 4.95%.

How Illinois treats capital gains

Illinois taxes capital gains as ordinary income at a flat 4.95% rate.

A worked example

Say you are a single filer in Illinois with $60,000 of taxable income who sells stock held over a year for a $25,000 long-term gain. Federal tax on the gain is $3,750 (all of it lands in the 15% bracket at this income; no NIIT applies below $200,000 MAGI). Illinois adds an estimated $1,238, for a combined $4,988, an effective 20.0% on the gain. These figures use the same math as the calculator, 2026 federal brackets per IRS Rev. Proc. 2025-32, and state figures from the Tax Foundation's State Individual Income Tax Rates and Brackets, 2026.

Frequently asked questions

Does Illinois tax capital gains?

Yes. Illinois taxes capital gains as ordinary income. Illinois taxes capital gains as ordinary income at a flat 4.95% rate.

What will I pay on a long-term gain in Illinois?

Combined, our worked example ($25,000 long-term gain on $60,000 of income, single) comes to $4,988: $3,750 federal plus $1,238 Illinois tax, an effective 20.0%.

Do I still owe federal capital gains tax in Illinois?

Yes. Federal capital gains tax (0%, 15%, or 20% long-term, ordinary rates short-term, plus the 3.8% NIIT for high earners) applies no matter your state. The free calculator estimates federal, NIIT, and Illinois tax together.

More

This page is general information, not tax, legal, or financial advice. Rates and rules can change and depend on your situation. Confirm details with a tax professional, the IRS, or your state's revenue department.

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