United States · Payroll withholding
Bonus tax calculator.
Enter your bonus and what you have earned so far this year. See the federal income tax, Social Security, Medicare and state amounts an employer withholds on it, and what lands in your pocket.
Most employers withhold federal income tax on a bonus at a flat 22% (37% on supplemental wages above $1,000,000 in a year), plus Social Security at 6.2% up to the $184,500 wage base and Medicare at 1.45%. That is withholding, not your final tax: the real bill is settled when you file.
Your bonus
Your estimate
How bonus withholding works
A bonus is supplemental wages. IRS Publication 15 (2026), section 7, lets an employer withhold federal income tax on supplemental wages at a flat 22%, and requires 37% on the part of supplemental wages paid to an employee in the calendar year that exceeds $1,000,000. Social Security tax is 6.2% on wages up to the $184,500 wage base for 2026. Medicare tax is 1.45% with no limit, plus a 0.9% Additional Medicare Tax withheld on wages above $200,000 in a calendar year (Publication 15, section 2).
Formula: federal = 22% × (bonus − 401(k) deferral) up to the $1,000,000 line, 37% above it. Social Security = 6.2% × the part of the bonus under the wage base. Medicare = 1.45% × bonus. Additional Medicare = 0.9% × the part of the bonus above $200,000 of total wages. State = your rate × (bonus − deferral).
Worked example
A $10,000 bonus, with $100,000 already paid this year and a 5% state rate: federal $2,200, Social Security $620, Medicare $145, state $500, so $3,465 is withheld and $6,535 is left. The form is preloaded with this example.
What this page does not do
- Withholding is not your tax. Your actual tax comes from your whole-year income and brackets, so a refund or a balance due can follow. Compare with the federal income tax page.
- An employer may instead add the bonus to regular pay and withhold on the total (the aggregate method). That is not modelled, and results can differ, mainly in the federal line.
- State and local withholding rules vary; the percentage is yours to enter. The $1,000,000 line is measured across the employer and its related employers.
- Pre-tax items other than a 401(k) deferral, such as HSA or health premiums, are not modelled.
Official source: IRS Publication 15 (2026), Employer’s Tax Guide, sections 2 and 7, read October 4, 2026.
Frequently asked questions
Is a bonus taxed at a higher rate?
The withholding is often a flat 22% federal rate, which can look high or low next to your normal paycheck. The bonus is added to your income for the year and taxed at your actual rates when you file.
Will I get the withheld money back?
Possibly. If the flat 22% exceeds your real marginal rate on the bonus, the difference comes back as a lower balance due or a larger refund; if it is lower, you may owe more.
Does a 401(k) contribution lower bonus tax?
A pre-tax 401(k) deferral lowers the wages used for income tax withholding, but Social Security and Medicare still apply to the full bonus.
Why is Social Security zero on a large bonus?
Social Security applies only up to the wage base ($184,500 in 2026). If your pay so far already exceeds it, none is withheld on the bonus.
Estimate only
This page is educational and is not tax advice. It estimates payroll withholding using the IRS 2026 figures shown; your employer's payroll system and your final return are what count. Calculations run in your browser; nothing is sent anywhere.