How is federal bonus withholding estimated?
For a separately identified supplemental wage payment, Publication 15 permits a flat 22% federal withholding method in many cases when annual supplemental wages are at or below $1 million. The portion above the threshold is generally withheld at 37%.
Is 22% the final tax rate on a bonus?
No. Withholding is a prepayment of income tax, not necessarily the final tax rate. Your tax return combines the bonus with other taxable income and applies the tax rules that fit your situation.
Are Social Security and Medicare withheld from bonuses?
Generally, taxable bonuses are wages for payroll-tax purposes. This calculator uses the 2026 Social Security wage base, Medicare rate and employer Additional Medicare withholding threshold.
Why does the calculator ask for year-to-date wages?
Year-to-date wages determine how much of the bonus is still subject to Social Security tax and whether Additional Medicare withholding begins during the payment.
Frequently asked questions
Sources and methodology
The calculator uses the current federal figures or official agency guidance described below where those rules apply. State-specific results should always be checked with the relevant state tax authority.