capitalgainstaxcalc

Illinois · Tax year 2026

Illinois Capital Gains Tax Calculator

Flat 4.95% on everything. No preferential rate, no exclusion.

Showing an example. Change any figure.

Your sale
Not sure? Work it out from the dates

What counts as cost basis?

What you paid, plus commissions and fees. Your gain is the sale proceeds less this. For an inherited asset it is usually the market value at the date of death, not what the person who left it to you paid.

About you
Why are some states unavailable?

States we can't yet compute for 2026 stay in the list, disabled, so a missing state is never mistaken for one with no tax. How states are checked.

Itemizing your deductions?
Standard or itemized?

The standard deduction is a fixed amount everyone can subtract — $16,100 single for 2026. Itemizing means totting up specific costs instead: mortgage interest, state taxes, charitable gifts. Take whichever is larger; most people take the standard.

How Illinois taxes a capital gain

Statutory authority: 35 ILCS 5/201; Ill. Dept. of Revenue, Income Tax Rates

One rate, applied to everything

Illinois taxes individual income at a flat 4.95%, and capital gains are income. There is no preferential long-term rate, no exclusion, no holding-period distinction and no bracket to climb. A $10,000 gain and a $10,000,000 gain are taxed at the same percentage.

That makes Illinois unusually easy to plan around. The marginal rate on your next dollar of gain is 4.95% regardless of how much you have already realized, so the timing games that matter in graduated states — spreading a sale across tax years to stay under a threshold — buy you nothing at state level here. They can still be worth doing for federal reasons.

The rate has not moved since 2017

The 4.95% rate took effect on 1 July 2017 and has been unchanged since. It is a standing statutory rate rather than an annually indexed figure, which means it does not drift each January the way bracket thresholds do in other states — it changes only when the legislature changes it.

A graduated-rate amendment was put to Illinois voters in 2020 and rejected, leaving the flat structure in place. Any future move to graduated rates would require a constitutional amendment, not merely a statute.

What the flat rate does not soften

Because Illinois offers no preferential treatment, the state rate applies fully to gains that are federally advantaged. A taxpayer whose long-term gain falls entirely in the federal 0% band still owes Illinois 4.95% on the whole thing. For modest gains at modest incomes, the state can easily be the larger of the two bills.

The federal side is unchanged: 0/15/20% on long-term gains, ordinary rates on short-term, the 3.8% net investment income tax above the thresholds, the Section 121 exclusion on a main home and Section 1250 recapture on a rental.

What the calculator shows you, and what it leaves out

Because the rate is flat and the structure has no thresholds, Illinois is one of the few states where this calculator can give you a state figure with no approximation in the rate itself. There is no bracket ladder to stack a gain against, and no year-end indexed table to wait for — so unlike California or Ohio, the Illinois number here is not carrying a prior-year figure.

What it does approximate is the base. Illinois starts from federal adjusted gross income and then applies its own additions and subtractions, which this calculator does not model. For a straightforward salary-plus-sale situation the difference is small; if your return carries significant Illinois-specific adjustments, treat the state line as indicative. The full list of what is and is not modeled is on the methodology page.

A worked Illinois example

Computed by the calculator's own engine when this page was built, so it updates with the tax data.

A $200,000 gain that is federally cheap and locally not

A single Illinois resident earning $120,000 realizes a $200,000 long-term gain.

Taxable income after deduction
$303,900
Taxable gain
$200,000
Tax owed without the sale
$17,570
Tax the sale added
$34,560
of which net investment income tax
$4,560
Total federal tax
$52,130
Illinois state tax
$9,900
Effective rate on the gain
17.28%

The Illinois figure is simply 4.95% of the gain — no stacking, no thresholds, nothing to optimize. All the complexity in this example is federal.

Caveats on this example (1)
  • Net investment income was derived from capital gains and qualified dividends only. Interest, non-qualified dividends, rents, royalties and passive business income included in your other income are also net investment income under IRC 1411(c) and are not counted here.
Show the working — 13 steps, each with its citation
  1. Net short-term capital gain or loss for the year$0Short-term / long-term nettingIRC 1222; IRS Pub. 550

    Assets held one year or less. Taxed at ordinary rates if a net gain.

  2. Net long-term capital gain or loss for the year$200,000Short-term / long-term nettingIRC 1222; IRS Pub. 550

    Assets held more than one year. Eligible for the 0/15/20% rates.

  3. Standard deduction-$16,100Deduction from adjusted gross incomeRev. Proc. 2025-32 4.14(1) (IRC 63(c)(2))

    Adjusted gross income of $320,000 less $16,100.

  4. Taxable income$303,900Taxable incomeIRC 63(a)

    The figure the rate tables and the capital gain ceilings are both measured against.

  5. Ordinary income taxed at 10%$1,240Ordinary income tax bracketsRev. Proc. 2025-32 4.01 (IRC 1(j)(2))

    $12,400 of taxable income between $0 and $12,400.

  6. Ordinary income taxed at 12%$4,560Ordinary income tax bracketsRev. Proc. 2025-32 4.01 (IRC 1(j)(2))

    $38,000 of taxable income between $12,400 and $50,400.

  7. Ordinary income taxed at 22%$11,770Ordinary income tax bracketsRev. Proc. 2025-32 4.01 (IRC 1(j)(2))

    $53,500 of taxable income between $50,400 and $103,900.

  8. Ordinary income stacked below the long-term gain$103,900LTCG bracket stackingIRC 1(h); Schedule D Tax Worksheet, Form 1040 instructions

    Long-term gain is taxed by reference to where it sits ON TOP of $103,900 of other taxable income, not from the bottom of the rate table.

  9. Long-term gain taxed at 15%$30,000LTCG bracket stackingRev. Proc. 2025-32 4.03 (IRC 1(h), 1(j)(5))

    Gain between the $49,450 zero-rate ceiling and the $545,500 15% ceiling.

  10. Net investment income tax threshold$200,000IRC 1411 thresholdIRC 1411(a)-(b); 26 C.F.R. 1.1411-2

    Modified AGI of $320,000 against the $200,000 threshold for a single filer. This threshold is statutory and is not adjusted for inflation.

  11. Net investment income tax at 3.8%$4,560Net investment income taxIRC 1411(a)-(b); 26 C.F.R. 1.1411-2

    3.8% of $120,000, the lesser of net investment income ($200,000) and the amount by which modified AGI exceeds the threshold ($120,000). Here the binding figure is the excess of modified AGI over the threshold.

  12. Illinois income tax at 4.95%$9,900State flat income tax on capital gainsIll. Dept. of Revenue, Income Tax Rates (35 ILCS 5/201)

    Flat 4.95% of net income, effective 1 July 2017 and unchanged since. Capital gains are taxed as ordinary income with no preferential rate and no exclusion. A standing statutory rate, not annually indexed.

  13. Total tax$62,030Sum of all tax stepsRev. Proc. 2025-32 (I.R.B. 2025-45)

    $62,030 on $320,000 of total income, an effective rate of 19.38%.

What this calculator does not cover for Illinois

The Illinois figure stacks your gain on your federal ordinary taxable income. Illinois computes its own taxable income with its own additions and subtractions, which are not modeled here — so treat the state number as a close approximation for a straightforward wage-and-sale situation, and as a rough one if your return carries significant state adjustments.

Full-year residency is assumed throughout. Part-year residents, non-residents, and gains sourced to property in another state all turn on rules this calculator does not model. The complete list of what is in and out of scope is on the methodology page.

Other states

The 2026 capital gains tax calculator covers the federal rules that apply wherever you live, and the state comparison sets every covered state side by side.