Bonuses always seem to shrink on the way to your bank account. That’s not because bonuses are taxed at a special rate — it’s because employers withhold differently on “supplemental wages.” This calculator shows exactly what gets withheld from a bonus in 2026 under the two methods the IRS allows, adds Social Security, Medicare, state tax and any 401(k) deferral, and tells you what you’ll actually take home.
How to use the bonus tax calculator
- Enter the gross bonus.
- Choose the federal withholding method — flat 22% (most common when the bonus is paid separately) or aggregate.
- For the aggregate method, enter your regular salary, pay frequency and W-4 filing status.
- Enter the wages paid so far this year so the calculator can apply the Social Security wage base and the Additional Medicare threshold.
- Optionally add a 401(k) deferral, your state’s withholding rate, or a take-home amount to gross up.
How bonus withholding is calculated
For the aggregate method the calculator annualizes the combined paycheck and applies the IRS Publication 15-T annual percentage method tables for 2026 (standard withholding, Form W-4 2020 or later with no extra adjustments). A 401(k) deferral reduces income-tax withholding but not Social Security and Medicare.
Worked example
A single employee earning $80,000 a year, paid every two weeks, receives a $10,000 bonus after earning $40,000 so far this year.
Flat method: federal = 10,000 × 22% = $2,200
Social Security = $620; Medicare = $145
Take-home = 10,000 − 2,965 = $7,035 (29.65% withheld)
Aggregate method: withholding on a $13,076.92 paycheck minus withholding on $3,076.92 = $2,821.70 federal → take-home $6,413.30
The aggregate method withholds about $622 more here, because a $13,077 paycheck annualizes to $340,000 — deep in the 35% withholding bracket. On the actual tax return, the bonus is simply added to the year’s $80,000 salary and mostly taxed at 22%, so the extra withholding would come back as part of a refund.
To hand the employee exactly $5,000 after withholding with the flat method, the employer would need to pay a gross bonus of about $7,107.
2026 rules for supplemental wages
| Item | 2026 figure | Source |
|---|---|---|
| Flat supplemental rate | 22% | IRS Publication 15 |
| Mandatory rate over $1 million of supplemental wages | 37% | IRS Publication 15 |
| Social Security | 6.2% on wages up to $184,500 | SSA |
| Medicare | 1.45%, plus 0.9% withheld on wages over $200,000 | IRS Publication 15 |
Ways to keep more of a bonus
- Defer some into a 401(k) if your plan allows deferrals from bonuses; it reduces income tax now, within the annual contribution limit.
- Check your total withholding. If the bonus will push your withholding well above your actual tax, you may be able to adjust your W-4 for the rest of the year — the tax refund estimator shows where you stand.
- Remember state rules. Many states also use a flat supplemental rate; a few have no income tax at all.
This is an estimate of withholding, not of your final tax, and not tax advice. Your employer's payroll system, your W-4 entries and state rules determine the actual amounts.
Frequently asked questions
How much tax is withheld from a bonus in 2026?
When a bonus is paid separately from regular wages, most employers withhold federal income tax at the flat supplemental rate of 22% (IRS Publication 15). Social Security (6.2%) and Medicare (1.45%) also apply, plus any state tax — so roughly 30% or more is commonly withheld.
What happens to bonuses over $1 million?
Once an employee's supplemental wages from an employer exceed $1 million in a calendar year, the excess must be withheld at 37%, the top income tax rate, regardless of the employee's Form W-4.
What is the aggregate method?
The employer adds the bonus to a regular paycheck, figures withholding on the combined amount as if it were normal pay for that period, and subtracts what would have been withheld from the regular pay alone. Because the combined check looks like a very high annual salary, the aggregate method often withholds more than 22% on large bonuses.
Are bonuses taxed more than regular pay?
No. Bonuses are ordinary wages and are taxed at the same rates as salary when you file your return. Only the withholding differs. If too much is withheld, you get it back as part of your refund; if too little, you owe the difference.
How do I gross up a bonus?
Grossing up means paying a larger gross bonus so that the employee receives a set amount after withholding. Enter the desired take-home amount and the calculator finds the gross bonus that produces it with the same taxes and deductions.