Illinois Tax Calculator 2025
Calculate your Illinois state income tax with our comprehensive 2025 calculator featuring a simple 4.95% flat rate, standard deductions, and advanced tax planning tools for the Prairie State.
Calculate Your Illinois State Tax
Enter your income information to calculate Illinois state income tax and explore tax optimization strategies.
Illinois Tax System 2025
Illinois operates a flat income tax system with a single rate of 4.95% on all income levels. This simplified structure makes tax calculation straightforward for all Illinois residents and businesses.
Flat Tax Structure
- 4.95% on all income levels
- No tax brackets or progressive rates
- Same rate for individuals and businesses
- Simplified tax filing process
Standard Deductions (2025)
- Single: $2,825
- Married Filing Jointly: $5,650
- Married Filing Separately: $2,825
- Head of Household: $4,238
Illinois Tax Benefits
Despite its flat tax structure, Illinois offers several tax benefits and credits that can reduce your overall state tax burden.
- Personal Exemptions: $2,375 per taxpayer and dependent
- Retirement Income Subtraction: Significant deductions for retirement income
- Property Tax Credit: Credits for property taxes paid
- Education Credits: Credits for education expenses
- Military Benefits: Active duty military pay exemptions
- No Social Security Tax: Social Security benefits not taxed
Illinois Residency Rules
Understanding Illinois residency is important for determining your tax obligations in the Prairie State.
Full-Year Resident
You're considered an Illinois resident if your permanent home is in Illinois or you spend more than 183 days in the state during the tax year.
Part-Year Resident
If you moved to or from Illinois during the year, you may file as a part-year resident and pay tax only on income earned while an Illinois resident.
Non-Resident
Non-residents pay Illinois tax only on income sourced within Illinois, such as wages earned in Illinois or rental income from Illinois property.
Frequently Asked Questions
What is Illinois's tax rate for 2025?
Illinois has a flat income tax rate of 4.95% that applies to all income levels. This rate applies to both individuals and businesses, making Illinois one of the few states with a true flat tax system.
Does Illinois tax retirement income?
Illinois provides generous retirement income subtractions. Most retirement income, including pension distributions and retirement account withdrawals, may qualify for substantial deductions from Illinois taxable income.
Does Illinois tax Social Security benefits?
No, Illinois does not tax Social Security benefits. This makes Illinois attractive for retirees who want to minimize their state tax burden on Social Security income.
What is Illinois's standard deduction for 2025?
Illinois's standard deduction for 2025 is $2,825 for single filers, $5,650 for married filing jointly, $2,825 for married filing separately, and $4,238 for head of household filers.
How does Illinois compare to neighboring states?
Illinois's 4.95% flat rate is competitive with neighboring states. Indiana has a 3.23% flat rate, while Wisconsin and Iowa have progressive systems with higher top rates for high earners.
When are Illinois state taxes due?
Illinois state income tax returns are due on April 15th, the same date as federal returns. Illinois also requires quarterly estimated tax payments for those who expect to owe $1,000 or more in tax.