Illinois Bonus Tax Calculator 2026
Updated for the 2026 tax year · Last updated June 11, 2026
Your bonus take-home in Illinois
$6,540
You keep 65.4% of a $10,000 bonus · $3,460 withheld (34.6%)
| Bonus amount | $10,000 |
| Federal withholding (22%) | −$2,200 |
| Social Security (6.2%) | −$620 |
| Medicare (1.45%) | −$145 |
| Illinois state tax | −$495 |
| Net bonus | $6,540 |
Uses the IRS percentage method (flat 22% federal withholding on bonuses up to $1M) plus FICA and Illinois state withholding. This is withholding at payout — your final tax is settled when you file. Single filer, no pre-tax deductions. For guidance only, not tax advice.
How bonuses are taxed in Illinois
Illinois withholds a flat 4.95% on supplemental wages like bonuses, on top of federal withholding and FICA.
Bonus take-home examples in Illinois
$5,000 bonus
$3,270 take-home
$1,730 withheld · you keep 65.4%
$10,000 bonus
$6,540 take-home
$3,460 withheld · you keep 65.4%
Assumes a single filer with $65,000 base salary.
Illinois bonus tax FAQ
How much is a $10,000 bonus taxed in Illinois?
For 2026, a $10,000 bonus in Illinois has about $3,460 withheld (34.6%), leaving roughly $6,540 — assuming a single filer earning $65,000 in base salary.
How are bonuses taxed by the federal government in 2026?
The IRS treats bonuses as supplemental wages. Employers usually use the percentage method: a flat 22% federal withholding on bonuses up to $1 million, and 37% on any amount above $1 million, plus Social Security (6.2%) and Medicare (1.45%).
Does Illinois tax bonuses?
Yes. Illinois withholds 4.95% on bonuses as supplemental wages, in addition to federal tax and FICA.
Why was so much withheld from my bonus?
Bonus withholding often looks high because the flat 22% federal rate can exceed your normal paycheck withholding. It is only withholding, not your final tax — if too much was withheld, you get it back when you file your return.
Related calculators
- Illinois paycheck calculator
- Wisconsin bonus tax calculator
- Indiana bonus tax calculator
- Missouri bonus tax calculator
See all states on the bonus tax calculator hub.
Sources: IRS 2026 supplemental wage withholding (22% / 37%); SSA 2026 ($184,500 Social Security wage base); Illinois Department of Revenue; Tax Foundation, 2026 State Individual Income Tax Rates and Brackets (Feb 2026).
State tax assumptions: The $2,925 personal exemption is modeled as a standard deduction; its phase-out above $250,000 income is not modeled.