Bonus tax calculator, what is left after withholding.

A bonus feels smaller than expected because the payroll system holds back tax from it before you see it. This bonus tax calculator shows what is withheld from a bonus and what is left. It uses the flat federal method that the IRS describes for supplemental wages, adds Social Security and Medicare, and takes your own state and local rates if you type them. It shows withholding, which is not the same as the tax you owe for the year. The figures come from IRS Publication 15 (2026) and the IRS page on the Additional Medicare Tax, both read on 24 Oct 2026.

How to use it

1. Type the Amount and the Wages so far this year, before this bonus. Leave That amount is on the bonus before tax, or switch it to what you want to receive to work backwards to the bonus you would need.
2. Choose the Federal method: Flat 22% (IRS flat method), or My own federal rate if your employer uses the aggregate method or you know your rate.
3. Open Before tax, state and local to type a 401(k) deferral, other bonuses paid this year and your state and local rates.
4. Read Bonus after tax, then the line by line table. Copy result copies a line and Copy link to these numbers reopens the page with your inputs.

Working backwards from the amount you want

Say you want 10,000 in your pocket and your wages so far are 80,000. With the flat method and no state tax, 29.65 percent is withheld, so 70.35 percent of the bonus is left. The bonus needed is 10,000 / 0.7035 = about 14,214.64. Choose What I want to receive after tax and the page does this for you, including cases where a limit changes the rates part way. It uses the same withholding rules as the forward direction, so the answer is withholding, not final tax.

The figures used

Sources: irs.gov/publications/p15 and irs.gov, Additional Medicare Tax questions and answers, checked 24 Oct 2026. Rates and limits change, so check the current IRS figures before you rely on them.

Worked examples

A bonus of 10,000 with 80,000 of wages so far. Federal withholding at the flat rate is 22 percent of 10,000 = 2,200. Social Security is 6.2 percent of 10,000 = 620, because 80,000 is well under the limit. Medicare is 1.45 percent = 145. Together that is 2,965, or 29.65 percent, and the bonus after tax is 7,035. If your state takes 5 percent, that is another 500 and the bonus after tax is 6,535.

With a 2,000 deferral into a 401(k). If the 2,000 comes out before income tax only, the federal tax is 22 percent of 8,000 = 1,760. Social Security (620) and Medicare (145) still apply to the full 10,000 unless you tick the box that says it is also taken before them. The bonus after tax is 5,475, and 2,000 went into the account.

A bonus of 50,000 with 160,000 of wages so far. Only 24,500 is left under the Social Security limit of 184,500, so Social Security is 6.2 percent of 24,500 = 1,519. Medicare is 725. Wages pass 200,000 by 10,000 of this bonus, so the Additional Medicare Tax is 0.9 percent of 10,000 = 90. Federal withholding is 11,000. The bonus after tax is 36,666.

The flat method and the 37 percent rate

Under the flat method the employer withholds a fixed percentage of the bonus without adding it to your regular pay. For supplemental wages above 1,000,000 paid to one employee in a calendar year, the rate is 37 percent on the part over that line. With 900,000 of supplemental pay already this year and a new bonus of 300,000, the first 100,000 is withheld at 22 percent (22,000) and the other 200,000 at 37 percent (74,000), so the federal withholding is 96,000.

Different bonus sizes

With 80,000 of wages so far and the flat method, the withholding is the same share of each bonus until a limit is crossed, so the bonus after tax rises in a straight line:

These rows have no state or local tax. The 29.65 percent is 22 percent federal plus 6.2 percent Social Security plus 1.45 percent Medicare. A limit changes the share only when wages pass 184,500 (Social Security stops) or 200,000 (the Additional Medicare Tax starts), or when supplemental pay passes 1,000,000.

The aggregate method

Some employers instead add the bonus to your regular pay for the period, withhold tax on the total as if it were one paycheck and subtract what was already withheld. The result depends on your pay and the payroll tables, which this page does not hold. If you know the federal rate your payroll applied, choose My own federal rate. With 24 percent as an example, the same 10,000 bonus has 2,400 of federal withholding and leaves 6,835.

Withholding is not the tax you owe

The year’s tax is worked out on your return from all your income. If your employer held back more than you owe, you get a refund. If it held back less, you pay the rest. The only way to know is to work out your whole year. To see what a raise does to pay, try the pay raise calculator. To turn pay into an hourly figure, use the salary to hourly calculator, and for retirement savings see the 401k calculator.