Bonus Take-Home and Gross-Up Calculator

How much of your bonus do you actually keep?

Enter the bonus and what you have earned so far this year. It shows the check after federal supplemental withholding, Social Security, Medicare and state tax, whether that withholding was too much or too little against your real bracket, what a 401(k) deferral changes, and the gross bonus an employer must pay to leave a target amount in your pocket.

Planning arithmetic on rates you type in.

1. The bonus

Gross bonus ($)

Wages already paid this year, before the bonus ($)

Share of the bonus you put in a 401(k) (%)

2. Withholding on the bonus

Federal withholding rate on the bonus (%; 22 is the flat supplemental rate)

State and local withholding rate on the bonus (%)

3. What you really owe at the margin

Your federal bracket (%)

Your state and local marginal rate (%)

4. Payroll tax settings

Social Security wage base ($)

Social Security rate (%)

Medicare rate (%)

Additional Medicare threshold ($)

Additional Medicare rate (%)

5. A gross-up

Cash you want in the paycheck after tax ($)

Questions people ask

Why does my bonus check look so small?

Most employers withhold federal income tax on a bonus at a flat 22% (the supplemental rate), then take Social Security, Medicare and your state's share on top. With a state rate of 5% that is about 35 cents of every dollar before anything else. The tool lists each piece.

Is a bonus really taxed at a higher rate?

No. The extra withholding is not a higher tax. Withholding is a prepayment: the bonus is added to your income for the year and taxed at your real bracket when you file. If 22% was more than your bracket, the difference comes back as a refund; if your bracket is higher, you owe the rest. The tool shows which.

How much do I need to gross up to pay a bonus net?

Divide the net you want by what is left after every tax that applies, or let the tool solve it, including the Social Security cap and the Additional Medicare Tax once the wages pass their lines. This is what employers do when they promise a bonus after tax, for example a relocation or sign-on payment.

Does putting a bonus in a 401(k) help?

A deferral takes income tax off that part now, but not Social Security or Medicare, which are still taken on the full bonus. The table shows take-home and the after-tax value of the bonus at several deferral shares. Contribution limits and your plan's rules apply and are not checked here.

Is this tax or payroll advice?

No. It is arithmetic on rates you type in. It does not run a payroll, know your W-4 or your state's rules, or file anything. The federal rates in the boxes are U.S. figures that change; confirm them before relying on a number.

Not decided

Your W-4 and the aggregate withholding method some employers use instead of the flat rate, state rules (some states have their own supplemental rate or none), local and disability taxes, tax credits and phase-outs your extra income may trigger, 401(k) contribution limits and employer match, and any other pay in the same check. The defaults are placeholders, not current legal figures: check every rate against your pay stub and the current IRS Publication 15.