Bonus paycheck tax calculator explained
Last updated: 2026-08-14
A $1,000 bonus does not arrive as $1,000, and it usually does not arrive as anything close. Under the flat method a single filer sees about $703 of it. The reason is not that bonuses are taxed more heavily. It is that they are withheld differently, and the two are not the same thing.
Where the money goes
Bonuses count as supplemental wages, and so do commission, tips, and other one-off earnings. Under the flat method the federal rate on them is a fixed 22%, regardless of your actual bracket.
| Line | Amount |
|---|---|
| Bonus | $1,000.00 |
| Federal supplemental withholding at 22% | −$220.00 |
| Social Security at 6.2% | −$62.00 |
| Medicare at 1.45% | −$14.50 |
| Net (Texas, no state tax) | $703.50 |
FICA is the part people forget. The 22% is federal income tax only. Social Security and Medicare apply to bonus wages exactly as they apply to regular wages, adding another 7.65%. In a state with income tax, a third line comes off on top of these.
Flat and aggregate produce different paychecks
Employers can use either of two methods, and you generally do not get to choose.
The flat method treats the bonus as its own thing and withholds 22% of it. Simple, predictable, and completely blind to your actual bracket. If your marginal rate is 12%, it overwithholds. If your marginal rate is 32%, it underwithholds.
The aggregate method adds the bonus to your regular wages for that pay period, runs the whole combined amount through the normal percentage-method worksheet, then subtracts the withholding already attributable to your regular pay. What is left is withheld from the bonus.
Because that worksheet annualizes, a bonus paid in one period gets treated as though it repeats every period. A $10,000 bonus on a biweekly paycheck is annualized as $260,000 of extra income. The bracket that lands on is far above your real one, which is why the aggregate method can withhold nearly half of a large bonus.
The $1 million rule
Once your cumulative supplemental wages pass $1,000,000 in a calendar year, the excess is withheld at 37% rather than 22%. The threshold applies to the running total, not to any one payment, so a bonus can straddle it.
Say you have already received $999,000 in supplemental wages this year and a $2,000 bonus arrives. It splits:
- $1,000 falls below the threshold, withheld at 22% = $220
- $1,000 falls above it, withheld at 37% = $370
- Total federal withholding on that $2,000 bonus: $590
The same $2,000 bonus earlier in the year would have been withheld at $440.
None of this is your actual tax
This is the part worth holding onto. Withholding is a collection mechanism, not a tax rate. Every dollar of that bonus is ordinary income, taxed at your ordinary brackets on your return, exactly like salary.
If the flat 22% took more than your bracket required, the excess comes back as refund. If it took less, you owe the difference. The bonus itself is not taxed at a special rate and never was — it was only ever withheld at one.
Practical consequence: do not treat a heavily withheld bonus as money lost, and do not treat a lightly withheld one as money kept. If a large bonus is underwithheld relative to your bracket, adjusting Step 4(c) on your W-4 for the rest of the year is the cleaner fix than finding out in April.
Estimate a specific bonus
The bonus paycheck calculator runs both methods so you can see the spread between them on your own numbers. For the regular paycheck underneath it, use the U.S. paycheck calculator.
Related reading: how federal paycheck withholding works and how to calculate take-home pay.
Common questions
Is a bonus taxed at a higher rate?
No. It is withheld differently, not taxed differently. The flat method withholds a fixed percentage regardless of your bracket, which frequently over-withholds. Your actual tax on the bonus is settled at your ordinary rate when you file.
Why did nearly half my bonus disappear?
That is usually the aggregate method. It adds the bonus to your regular wages and annualises the combined figure, which pushes the calculation into a much higher apparent bracket for that one period.
Can I reduce withholding on a bonus?
Directing part of it into a 401(k) or HSA reduces taxable wages and therefore the withholding. You cannot simply ask payroll to withhold less on a supplemental payment, because the method is prescribed.
Will I get the over-withheld amount back?
Yes, as part of your refund when you file. The cost is the time your money spent with the government rather than with you.
Related reading
The rest of this series, and the calculators that let you run the idea on your own numbers.
More paycheck guides
Try it with your figures
See also all guides, every calculator, and the calculation methodology behind these estimates.