Bonus Calculator
Estimate net bonus after federal, state, FICA, and optional local withholding assumptions.
Selected state
California
State
California
Local tax
Estimated net bonus
$3,467.50
Estimated withholding
$1,532.50
FICA on bonus
$382.50
Local tax impact
$0.00
Using supplemental federal method
Why bonus withholding can look unusually high
A bonus is taxable wages, but the amount withheld from the check is not the same thing as the final tax owed on that income. Employers may use the federal supplemental flat-rate method when a bonus is identified separately, or combine it with regular wages and calculate withholding on the larger payroll amount. Social Security, Medicare, state, and sometimes local withholding can apply in addition to federal withholding.
Use the method shown on your payroll statement when you know it. The flat option models the federal supplemental rate; the annualized option models the bonus with the rest of the year's pay. Your tax return ultimately reconciles withholding against your actual annual income, deductions, and credits.
Worked example
$5,000 separately paid bonus
- Federal supplemental withholding at 22%: $1,100.
- Social Security at 6.2%: $310, if still below the annual wage base.
- Medicare at 1.45%: $72.50, before any Additional Medicare Tax.
That leaves $3,517.50 before state or local withholding and before any benefit deductions.
Before you rely on the result
- Confirm whether the bonus is separate from or combined with regular wages.
- Enter year-to-date wages when Social Security or Additional Medicare thresholds may matter.
- Treat the result as withholding, not a prediction of the final tax return.
- Compare the estimate with the tax lines on the actual bonus statement.
IRS Publication 15See the supplemental wages section for federal payroll-withholding methods and limits.