100% Free • No Sign-up • Official 2026 IL Figures
Illinois Income Tax Calculator (2026)
Estimate your 2026 Illinois state income tax — a flat 4.95% rate with $2,925 personal exemptions and a property tax credit. No sign-up, no cost.
Estimate Your IL Tax
IL offers a 5% credit on property tax paid on your principal residence.
Exemptions—
Illinois taxable income—
IL income tax (4.95%)—
Property tax credit (5%)—
Net IL tax—
Effective rate—
Illinois starts from federal AGI, then subtracts a $2,925 exemption for each filer and dependent. Tax is a flat 4.95% of the remainder.
How Illinois Income Tax Works
Illinois is one of the few states with a true flat income tax written into its constitution: 4.95% on every dollar of taxable income. There are no brackets and no marginal-rate math, but exemptions and credits still matter.
- Flat 4.95% rate. Every dollar of Illinois taxable income is taxed at 4.95%.
- $2,925 personal exemption. Each filer (and spouse on a joint return) plus each dependent gets a $2,925 exemption subtracted before the rate applies.
- 5% property tax credit. Homeowners get a credit worth 5% of property tax paid on a principal residence, subtracted directly from the tax bill.
- Starts from federal AGI. Illinois base income begins with federal adjusted gross income, with a handful of additions and subtractions.
IL tax = (AGI − $2,925 × exemptions) × 4.95% − property tax credit
Worked Example: Single, $80,000, No Dependents
Take a single filer earning $80,000 with no dependents and no property tax credit:
| Calculation | Amount | |
|---|---|---|
| Gross income | $80,000.00 | |
| Less: personal exemption | 1 × $2,925 | −$2,925.00 |
| Illinois taxable income | $80,000 − $2,925 | $77,075.00 |
| IL tax | $77,075 × 4.95% | $3,815.21 |
| Effective rate | $3,815.21 ÷ $80,000 | 4.77% |
A married couple filing jointly with two children would subtract four exemptions ($11,700), bringing taxable income to $68,300 and tax to $3,380.85.
Frequently Asked Questions
Yes. The Illinois constitution requires a single flat rate, currently 4.95%. A graduated-rate proposal (the “Fair Tax” amendment) failed at the ballot in 2020, so the flat tax remains.
$2,925 per person for 2026 — one for you, one for your spouse on a joint return, and one for each dependent. It is subtracted from income before the 4.95% rate is applied.
You can claim a credit equal to 5% of the property tax you paid on your principal residence during the year. It reduces your IL tax bill dollar-for-dollar (it is nonrefundable).
Illinois fully exempts most retirement income — including Social Security, pensions, and IRA/401(k) distributions — via a subtraction from federal AGI. Only a few states are this generous.
Illinois base income starts with your federal adjusted gross income (AGI), then applies Illinois-specific additions (like federally exempt municipal bond interest) and subtractions (like retirement income).
No — it is an estimate for planning purposes only. It models wage income with exemptions and the property tax credit; business, investment, and multi-state situations can differ. Verify with the Illinois Department of Revenue or a licensed tax professional.
Disclaimer: Estimates only — not tax advice. Verify with the Illinois Department of Revenue or a tax professional.