Illinois paycheck withholding calculator
Estimate how your paycheck withholding compares with a simplified annual Illinois income tax estimate. Enter your yearly wages and the state tax amounts from your paystub. Review the assumptions before changing payroll settings.
Illinois tax snapshot: Illinois taxes wages at a flat 4.95% rate. The Illinois standard deduction in this estimate is $2,775 for single filers — confirm the current-year figure in state instructions. To change Illinois withholding, file Illinois Form IL-W-4 with your employer.
Check your Illinois paycheck withholding
Enter your yearly wages and the state tax amounts from your paystub. This is a planning estimate, not your final state tax bill.
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Illinois income tax brackets (2026)
Illinois uses a flat 4.95% rate on taxable wages. The standard deduction is $2,775 for single filers.
Flat-rate states still require attention: local taxes, credits, and employer payroll rules can change your withholding. This estimate is simplified.
Chicago has a 10.125% sales tax. Some Illinois municipalities have local income taxes.
How to adjust Illinois withholding
File Illinois Form IL-W-4 with your employer to change Illinois paycheck withholding. Confirm you have the current-year version, enter only the lines your situation requires, and check your next paystub's state-tax line to verify the change took effect within one or two pay periods.
What is the Illinois state income tax rate?
Illinois taxes wage income at a flat 4.95% rate. This is a planning estimate — check current state instructions for your filing status and year.
What form changes Illinois withholding?
Illinois Form IL-W-4. Ask HR for the current-year version; payroll generally applies the change within one or two pay periods.