RUV CalculatorIllinois Income Tax Calculator 2026https://calc.ruvlabs.com/c/federal-income-tax/illinois
Illinois Income Tax Calculator 2026
Federal and state, added up
Income tax
Tax
State income tax
Refund Or Owed
Effective Rate
Advanced options
Breakdown
State applied
Taxable Income
Deduction Used
Marginal Rate
State schedule year
Combined marginal rate
After Tax Income
The standard deduction was used — itemising would come out smaller.
Federal plus Illinois state comes to $14,077.50, an effective rate of 16.560%.
Illinois's flat 4.95% income tax
Illinois taxes income at a flat 4.95%, whatever the amount and filing status. The calculator applies no Illinois standard deduction; Illinois's personal exemptions and credits are not modelled, so the estimate can run a little high.
These rates have been unchanged since 2017. It was checked on 2026-09-30 against Illinois DOR income tax rates page (4.95%).
Illinois and federal income tax by income
At the calculator's default $85,000, Illinois takes $4,208 of a $14,078 total income tax bill, or 30%. Filing status matters too: a married couple filing jointly on $170,000 owes Illinois $8,415 — exactly what two single filers earning $85,000 each would pay.
Single filer, standard deductions only
Gross income
Illinois tax
Illinois rate
Federal tax
Combined effective rate
$30,000
$1,485
4.95%
$1,420
9.68%
$50,000
$2,475
4.95%
$3,820
12.59%
$65,000
$3,218
4.95%
$5,620
13.60%
$85,000 (default)
$4,208
4.95%
$9,870
16.56%
$100,000
$4,950
4.95%
$13,170
18.12%
$125,000
$6,188
4.95%
$18,734
19.94%
$200,000
$9,900
4.95%
$36,734
23.32%
$300,000
$14,850
4.95%
$68,134
27.66%
$400,000
$19,800
4.95%
$103,134
30.73%
Marginal tax rate in Illinois
The next dollar a single filer earns above $85,000 is taxed at 26.95%: 22% federal and 4.95% by Illinois. Because Illinois's rate is flat, its share of a raise stays 4.95% at any income.
A flat 4.95% on taxable income, the same for every filing status (2017 schedule).
How much Illinois income tax is due on $85,000?
For a single filer, $4,208 to Illinois and $9,870 in federal income tax — $14,078 in all, an effective rate of 16.56%. That leaves $70,923 before Social Security and Medicare.
Does Illinois have a standard deduction?
No fixed amount the calculator applies — Illinois's rates go straight onto income, as explained above.
How much of a $5,000 raise goes to Illinois?
$248 for a single filer at $85,000, next to $1,100 of federal income tax — Illinois keeps 18% of the income tax on the raise.
Sources
Official documents the rates and rules on this page come from.
This is a reference calculation using common tax assumptions and is not a substitute for professional advice. We accept no liability for decisions made from it — see the terms of use for details.