Illinois State Income Tax Calculator
Calculate your 2026 Illinois state income tax. See your bracket breakdown, effective rate, and how Illinois compares to neighboring states.
Your Tax Inputs
The annual amount is gross income minus entered pre-tax deductions and modeled federal and state income tax. Monthly and weekly amounts divide it by 12 and 52. These allocations exclude Social Security and Medicare (FICA), local taxes, other payroll taxes, and unmodeled paycheck deductions. They do not estimate paycheck take-home or actual withholding.
Effective State Income Tax Rate vs Neighboring States
About Illinois state taxes (Tax year 2026)
Illinois has a flat income tax rate of 4.95% and no standard deduction. The 2026 basic exemption is $2,925 per eligible person. The allowance is unavailable above $500,000 in federal adjusted gross income for joint filers or $250,000 for other filing statuses.
Illinois ended its 1% state grocery tax on January 1, 2026. Municipalities and counties can adopt a 1% local grocery tax. Regional transit or Metro East taxes can still apply where applicable.
Illinois's 4.95% flat rate is near the national average, but its combined sales tax rate of 8.98% is among the highest in the nation.
Filing in Illinois: returns for tax year 2026 are administered by the Illinois Department of Revenue and are generally filed in 2027 by the federal April deadline unless Illinois declares a state-specific extension. Tax type on this return: Flat. Top marginal rate: 4.95%. State sales-tax rate: 6.25%. For the most current contact info, see the Federation of Tax Administrators directory.
Illinois — What is Illinois's income tax rate? Illinois has a flat income tax rate of 4.95% on all taxable income. The state constitution mandates a flat rate structure.
Illinois — Does Illinois tax groceries? Illinois ended its 1% state grocery tax on January 1, 2026. Municipalities and counties can adopt a 1% local grocery tax. Regional transit or Metro East taxes can still apply where applicable.
Illinois — Does Illinois have a standard deduction? Illinois has no standard deduction. The 2026 basic exemption is $2,925 per eligible person, subject to income and dependent rules.
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How this page is reviewed
See methodology, assumptions & sources
| Risk tier | High YMYL |
|---|---|
| Author | Calculover Editorial Team Tax education |
| Editorial owner | Calculover Tax & Payroll Desk State-tax methodology owner |
| Reviewer | Calculover Editorial Review Government-source and limitation review |
| Last reviewed | 2026-11-06 |
| Last verified | 2026-11-06 |
| Data effective date | 2026-01-01 |
| Jurisdiction | Illinois |
Methodology
These pages estimate annual state income tax for the selected 2026 jurisdiction and filing status. The route's coverage panel identifies the supported income basis, deductions, credits and exclusions.
Assumptions
- Enter the income basis and eligible pre-tax deductions requested by the calculator; gross wages, federal AGI and state AGI are not interchangeable.
- Some methods require confirmed state facts or explicit projection assumptions. An unavailable component is not zero tax.
Limitations
- The estimate excludes unmodeled income, adjustments, local taxes and special filing situations. Utah's indexed-credit assumptions remain provisional while final 2026 instructions are pending.
- Annual liability differs from withholding and paycheck take-home. Confirm the current official forms and source versions for a complete return.
Sources
- State Tax Rates, Federation of Tax Administrators
- State Individual Income Tax Rates and Brackets, Tax Foundation
- State Government Resources, Internal Revenue Service
Professional guidance: This page is for state-tax education only and is not tax, legal, financial, or investment advice. State tax decisions and multi-state filing should be reviewed with a CPA or enrolled agent licensed in the relevant states.