How to calculate bonus tax withholding
Enter the gross bonus, expected annual wage income before the bonus, filing status and year-to-date payroll wages paid by this employer. The calculator estimates take-home pay under the federal percentage method, adds payroll and optional state withholding, then compares the federal withholding deposit with a simplified estimate of the extra federal income tax on the bonus.
What is the federal bonus withholding rate for 2026?
IRS Publication 15 says the optional flat percentage-method rate for separately identified supplemental wages remains 22% when the employer meets the applicable conditions. If supplemental wages paid by the employer to an employee exceed $1,000,000 in the calendar year, the excess is subject to mandatory 37% withholding. A bonus paid with regular wages and not separately identified is handled as regular wages for that payroll period. In eligible cases, an employer may use the aggregate method instead.
This calculator models the percentage method. It does not reproduce an employer’s aggregate calculation, which depends on payroll-period wages and withholding details. Your paystub can therefore differ from this estimate.
How much tax is withheld from a bonus?
There is no single all-in percentage. Federal income-tax withholding is only one line. The calculator separately estimates Social Security, Medicare, Additional Medicare withholding when the employer’s $200,000 threshold is crossed, and an optional state/local rate you enter.
- Social Security: 6.2% of eligible wages, only until that employer’s 2026 year-to-date wages reach the $184,500 wage base.
- Medicare: 1.45% of Medicare wages with no wage cap.
- Additional Medicare withholding: 0.9% on wages this employer pays above $200,000 year to date, regardless of filing status. The final Additional Medicare Tax liability uses a filing-status threshold on the tax return.
- 401(k): a traditional elective deferral can reduce federal income-tax wages, but generally remains subject to Social Security and Medicare. Plan rules and annual contribution limits may restrict the amount.
Withholding is not the final bonus tax
A bonus is generally taxed as ordinary income, not at a special final tax rate. The estimated federal tax on the bonus is the difference between a simplified annual federal tax calculation with and without the taxable bonus. It uses your filing status, the 2026 federal rate schedule and the basic standard deduction. It is not a complete tax return and omits credits, itemized deductions, other income and other adjustments.
The comparison shows how the modeled bonus withholding could affect your federal balance before considering all other withholding, income, deductions and credits. It is not a promise of a refund or a bill.
California, New York City and other state rates
State and local bonus withholding methods differ. To include an approximate amount, enter the combined state/local supplemental withholding rate supplied by your payroll or official tax agency. The calculator does not look up a state rate and does not calculate Canadian withholding.
2026 source notes
- IRS Publication 15 (2026), sections 5 and 7 — supplemental wages, federal withholding, Social Security and Medicare.
- IRS Publication 15-T (2026) — federal income-tax withholding methods.
- IRS Topic 560 — Additional Medicare Tax thresholds and withholding.
- Social Security Administration contribution and benefit base — 2026 wage base.
- IRS Revenue Procedure 2025-32 — 2026 individual tax brackets and standard deductions.
Figures use tax year 2026 rules available when this page was updated. This is an educational estimate, not tax, payroll or legal advice. Verify your paystub and current official guidance.
