How Illinois withholding works
Illinois uses a single 4.95% rate. Before applying it, payroll subtracts your allowances spread over the year:
| IL-W-4 line | Annual amount per allowance |
|---|---|
| Line 1 – yourself, spouse and dependents | $2,925 |
| Line 2 – age 65 or older, legally blind | $1,000 |
The Illinois Department of Revenue’s own example: a weekly wage of $800 with two Line 1 and two Line 2 allowances gives (800 − (2 × 2,925 + 2 × 1,000) ÷ 52) × 4.95% = $32.13. This calculator reproduces that figure in its tests.
Traditional 401(k) contributions are excluded from Illinois wages, so they lower your state withholding as well as your federal.
Worked example: $60,000 in Illinois
Single, $60,000 salary, paid every two weeks, Illinois
Gross pay is $2,307.69 per paycheck. Federal income tax is $193 and Social Security and Medicare $177. Illinois withholds $109. Take-home pay is $1,829 per paycheck, or $47,565 a year.
Take-home pay per paycheck$1,829.4126 paychecks a year
- Take-home pay per year
- $47,565
- Federal income tax withheld
- $193.08
- Illinois income tax withheld
- $108.664.95% flat
| Item | Per paycheck | Per year |
|---|---|---|
| Gross pay | $2,307.69 | $60,000.00 |
| Federal income tax | −$193.08 | −$5,020.08 |
| Social Security (6.2%) | −$143.08 | −$3,720.08 |
| Medicare (1.45%) | −$33.46 | −$869.96 |
| Illinois income tax | −$108.66 | −$2,825.16 |
| Take-home pay | $1,829.41 | $47,564.72 |
At $100,000 a year, take-home pay is about $74,375 a year.