Illinois Payroll Tax Calculator 2026
Calculate Illinois state income tax, federal withholding, Social Security, Medicare, and net take-home pay.
2026 Illinois tax rates · FICA · Illinois IL-W-4
State Income Tax
4.95% flat rate
Social Security
6.2%
Medicare
1.45%
State Form
Illinois IL-W-4
Calculate Your Illinois Paycheck
Enter your salary or hourly rate and get a full breakdown: Illinois state tax, federal income tax, Social Security, Medicare, and exact net pay.
Open Illinois Payroll Tax CalculatorFree · No signup · 2026 IRS & IL rates
Illinois Tax Guide
Illinois Payroll Tax Overview 2026
Illinois uses a flat 4.95% income tax rate. All taxable income is taxed at the same percentage, regardless of how much you earn. This makes payroll calculations straightforward.
Illinois has a constitutionally mandated flat 4.95% income tax. All attempts to switch to a graduated tax have been rejected by voters.
Illinois is unique in that its flat tax is written into the state constitution, requiring a voter referendum to change it.
Illinois Payroll Tax Summary
State Income Tax4.95% flat rate
Tax TypeFlat rate
Social Security6.2% on first $176,100
Medicare1.45% (+ 0.9% over $200K)
FUTA (employer)0.6% on first $7,000
Employee FormIllinois IL-W-4
FAQ
Illinois payroll tax questions
What is the Illinois income tax rate for 2026?
Illinois uses a flat 4.95% income tax rate on all taxable income. Unlike progressive-tax states, the same rate applies whether you earn $30,000 or $300,000. This makes Illinois payroll tax calculations simple and predictable.
What taxes do Illinois employees pay on their paycheck?
Illinois employees pay: (1) Federal income tax (based on W-4 withholding); (2) Social Security tax (6.2% on wages up to $176,100); (3) Medicare tax (1.45%, plus 0.9% on income over $200,000); (4) Illinois state income tax (4.95% flat rate); The employer matches the Social Security and Medicare portions.
What payroll withholding form do Illinois employees use?
Illinois employees complete Illinois IL-W-4 for state withholding in addition to the federal W-4. Employers use both forms to calculate the correct combined withholding amount.
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