How a Illinois paycheck is built
Every Illinois worker pays federal income tax, calculated on the W-4 you submitted to your employer using the IRS Publication 15-T tables. Federal income tax is followed by FICA: 6.2 percent Social Security up to the annual wage base, plus 1.45 percent Medicare on every dollar. The 0.9 percent Additional Medicare Tax applies once year-to-date wages cross $200,000 single or $250,000 married filing jointly.
Illinois adds a flat state income tax of approximately 4.95 percent. Verify the current rate with the Illinois Department of Revenue.
What changed recently in Illinois
- Flat 4.95% rate unchanged.
- Chicago Paid Leave and Paid Sick Leave Ordinance expanded in 2024.
- Tipped wage credit exists but Chicago is phasing it out by 2028.
Illinois payroll quirks workers should know
- No city income tax in Chicago.
- Cook County and other counties do not levy income tax.
- Illinois uses IL-W-4 form for state withholding.
Example breakdown
A hypothetical Illinois worker on a $65,000 annual salary, paid bi-weekly, single filer, no extra adjustments. Educational only, your real paycheck differs.
| Gross (bi-weekly) | $2,500.00 |
| Federal income tax | -$216.15 |
| Social Security (6.2%) | -$155.00 |
| Medicare (1.45%) | -$36.25 |
| Illinois state tax | -$123.75 |
| Estimated take-home | $1,968.85 |
Run your own numbers in the Illinois paycheck calculator.