Bonus Tax Calculator
Employers withhold a flat 22% federal on a bonus. Your bonus is actually taxed at your own brackets, stacked on your salary. See both, and the gap you may owe at filing.
A single filer with a $250,000 salary who gets a $100,000 bonus has $22,000 withheld for federal income tax, but the bonus adds $34,330 to the 2026 federal bill, leaving about $12,330 to pay when you file.
Withholding stays at 22% while the tax climbs
| Bonus | Withheld at 22% | Federal tax owed | Effective rate | Owed at filing |
|---|---|---|---|---|
| $25,000 | $5,500 | $8,080 | 32.3% | $2,580 |
| $50,000 | $11,000 | $16,830 | 33.7% | $5,830 |
| $100,000 | $22,000 | $34,330 | 34.3% | $12,330 |
| $250,000 | $55,000 | $86,830 | 34.7% | $31,830 |
| $500,000 | $110,000 | $176,196 | 35.2% | $66,196 |
Withholding is a guess, the brackets are the bill
A bonus is ordinary wage income. On your return it is added to your salary and taxed through the same brackets, so the cost is the difference between your tax with the bonus and your tax without it. On a $250,000 salary, a single filer is already in the 32% bracket, and a $100,000 bonus runs through 32% and then 35%. That is $34,330 of federal tax.
Payroll does not see any of that. Under the optional flat-rate method, your employer withholds 22% of the bonus for federal income tax, $22,000 here, and 37% only on supplemental wages over $1,000,000 in the year. The $12,330 difference is not withheld anywhere. It shows up as a balance due in April, and if it is large enough, an underpayment penalty.
RSU vests are supplemental wages too, withheld at the same 22%, so equity pay and a bonus in the same year widen the same gap. The RSU tax calculator runs that side, and why RSU withholding falls short explains it. For the deferrals, timing and account moves that lower the bill itself, see tax strategies for high-income W-2 employees.