Capital Gains Calculators
Illinois Capital Gains Tax Calculator
A flat 4.95% on every gain, no exceptions for holding period — but which account the gain comes from can be the difference between owing 4.95% and owing nothing at all.
Calculate your Illinois capital gains tax
Flat rate, no local tax anywhere — includes federal capital gains tax and NIIT.
Assumes this gain is realized in a taxable brokerage account. No Illinois city, including Chicago, levies its own income tax. This is a planning estimate — confirm with the Illinois Department of Revenue.
Brutally simple math, constitutionally locked in
Illinois taxes capital gains exactly like every other type of income: a single flat rate of 4.95%, with no distinction between short-term and long-term gains at the state level. A $200,000 gain costs $9,900 in Illinois tax whether you held the asset for a week or a decade. This flat structure isn't just policy — it's written directly into the Illinois constitution, which requires a non-graduated income tax. Illinois voters explicitly rejected a 2020 ballot measure that would have allowed a graduated (progressive) system instead, keeping the flat rate in place.
The exemption, and the cliff that eliminates it
Illinois allows a personal exemption — $2,925 per person for 2026 — that reduces taxable income before the 4.95% rate applies. But this exemption disappears entirely, not gradually, once adjusted gross income exceeds $250,000 (single) or $500,000 (married filing jointly). A large capital gain can easily push a filer's total AGI over that threshold for the year, eliminating an exemption they'd normally receive — a real, if modest, additional cost on top of the gain itself.
The insight that actually changes strategy: it's about the account, not the asset
| Where the gain is realized | Illinois state tax |
|---|---|
| Taxable brokerage account | 4.95%, no exceptions |
| Traditional 401(k) / IRA | $0 (retirement income is fully exempt) |
| Roth IRA / Roth 401(k) | $0, including at eventual withdrawal |
No local tax, everywhere
No city in Illinois, including Chicago, levies its own income tax — the flat 4.95% state rate is the complete state-and-local picture. This puts Illinois in the same "clean" category as North Carolina and Pennsylvania, rather than the layered local-tax complexity found in New York or Ohio.
Illinois's flat 4.95% rate, the constitutional requirement behind it, the personal exemption cliff, and the blanket retirement income exemption verified against multiple independent 2026 Illinois tax guides, consistent with our earlier validated research for the Illinois Paycheck Tax Calculator. This is a planning estimate — confirm with the Illinois Department of Revenue.
Frequently asked questions
Before you sell an appreciated asset in Illinois.
Does Illinois have a lower tax rate for long-term capital gains?
No. Illinois taxes all capital gains as ordinary income at its flat 4.95% rate, with no distinction between short-term and long-term holdings.
Why is Illinois's tax rate flat instead of progressive?
The Illinois constitution requires a non-graduated income tax. Voters explicitly rejected a 2020 ballot measure that would have allowed a progressive system, keeping the flat rate in place.
What happens to my Illinois personal exemption if I have a large capital gain?
The $2,925 per-person exemption is eliminated entirely, not phased out gradually, once your adjusted gross income exceeds $250,000 (single) or $500,000 (married filing jointly) — a threshold a large gain can easily push you over.
Does it matter which account I realize a capital gain in?
Significantly, for Illinois tax purposes. Gains realized inside a 401(k), IRA, or other qualified retirement account are completely exempt from Illinois tax, since the state exempts all retirement income. The identical gain in a taxable brokerage account faces the full 4.95%.
Does Illinois have local income taxes?
No. No Illinois city, including Chicago, levies its own income tax — the flat state rate is the complete picture.