Payroll · Supplemental wages · Tax year 2026

Bonus Paycheck Calculator: The Flat 22 Percent Withholding, Estimated

A bonus is supplemental wages. When it is paid separately from regular wages, most employers withhold federal income tax from it at a flat 22 percent, whatever the worker's own bracket is, and Social Security and Medicare come out on top of that. Enter the bonus and, if you know them, the wages already paid this year, and this calculator estimates each withholding line and the take-home amount. The 22 percent is withholding, an advance payment. It is not the final tax on the bonus, which is settled on the return.

Last reviewed: November 4, 2026.

Checked against IRS sources · Reviewed November 4, 2026

The bonus calculator

The payment Bonus amount before tax (dollars)

If part of the bonus goes into a 401(k) or a similar plan before tax, enter only the part that stays subject to withholding. Payroll figures the withholding on that part.

Already paid this year (optional) Regular wages paid so far in 2026, before this bonus (dollars, optional)

Your last pay stub shows year-to-date wages. This figure measures the room left under the Social Security wage base and the $200,000 Additional Medicare line.

Bonuses and other supplemental wages already paid in 2026 (dollars, optional)

Used only for the $1 million rule described below.

Estimate only. This tool gives a general estimate based on the figures you entered and the published IRS rules cited on this page. It is not tax advice, it is not a tax return, and it cannot be relied on to avoid any tax penalty. Tax law and IRS guidance change. Confirm your figures against the current IRS instructions for the form you file, or ask a qualified tax professional.

Nothing you enter is sent anywhere. The calculation runs in your browser.

withholding now, the return settles it

How the flat rate works

Publication 15, the IRS employer's tax guide, calls bonuses, commissions, severance pay, and similar payments made apart from regular wages supplemental wages, and gives employers two ways to figure the federal income tax withholding on them:

The flat rate method. When the payment is paid separately from regular wages, or is identified separately on the payroll record, the employer may withhold at a flat 22 percent. No other percentage is used under this method, and the worker's Form W-4 does not enter into it.
The aggregate method. When the payment is paid together with regular wages and is not identified separately, the two amounts are added and withheld on as a single wage payment for the period, under the ordinary percentage method. That is why a bonus inside a regular paycheck can be withheld at more than 22 percent of the bonus part.

One line overrides the 22 percent: when the supplemental wages paid to one employee in the calendar year pass $1 million, the rate on the part over $1 million is 37 percent. Publication 15 states the pair of rates together: 22 percent, and 37 percent if supplemental wages paid to an employee during the calendar year exceed $1 million. Almost no bonus reaches that line, but the calculator applies it when the figures entered cross it.

The Social Security and Medicare lines

A bonus is wages for payroll tax as well, figured on the same bases as every other paycheck:

Social Security, 6.2 percent, applies until the year's combined wages reach the 2026 wage base of $184,500, and then stops. A worker already over the base has nothing more withheld; a worker partway there is withheld only on the part of the bonus that fits underneath it.
Medicare, 1.45 percent, applies to the whole bonus, with no wage limit.
Additional Medicare, 0.9 percent, is withheld on the part of the year's wages over $200,000, including the part of this bonus that crosses that line (IRS Topic No. 751).

The eight state paycheck calculators on this site work through the same bases for regular pay: Pennsylvania, Washington, Illinois, New Jersey, Ohio, Michigan, South Carolina, and Virginia.

Withholding is not the final tax

The figure this calculator returns is an estimate of one paycheck, nothing more. On the tax return, the bonus is ordinary wage income, added to salary and taxed at the worker's own marginal rates after deductions and credits. If the worker's marginal rate is below 22 percent, the flat rate will have taken out more than the tax the bonus adds, and the difference comes back through the refund calculation. If the marginal rate is above 22 percent, the return may show an amount still due. Neither outcome is an error by the employer: the flat rate is a withholding rule, not a measurement of anyone's tax.

What this estimate does not include

State and local withholding. States set their own treatment of bonuses, some with their own supplemental rates, and no state figure is estimated here.
Amounts taken out before tax beyond the adjustment described in the form, and amounts taken out after tax, such as garnishments or benefit repayments.
The employer's share of Social Security and Medicare, which is paid by the employer and never appears in the worker's take-home pay.

Questions and answers

Why was 22 percent taken from my bonus when my own tax rate is lower?

Because the 22 percent is a withholding rate set by Publication 15 for supplemental wages paid separately, not a rate figured from your bracket or your Form W-4. Withholding is an advance payment toward the year's tax. On the return the bonus is taxed as ordinary wages alongside everything else, and any withholding beyond the final tax comes back through the refund calculation.

Are commissions figured the same way?

Yes. Commissions are supplemental wages in Publication 15, like bonuses, so the same two methods apply: the flat 22 percent when the payment is identified separately, or the aggregate method when it is paid together with regular wages and not identified separately.

My bonus arrived inside my regular paycheck and the withholding looks higher than 22 percent. Why?

That is the aggregate method at work. When a bonus is paid together with regular wages without being identified separately, Publication 15 treats the combined amount as one wage payment for the period, and the percentage method annualizes it, which can withhold more than 22 percent of the bonus part. The return reconciles the total at the end of the year either way.

Does the 22 percent change the rate my bonus is actually taxed at?

No. A bonus is ordinary wage income on the return, taxed at the same marginal rates as salary. The flat rate only decides how much is taken out on payday. Whether 22 percent turns out to be more or less than the tax the bonus adds depends on the whole return: total income, deductions, and credits.

Sources

IRS, Publication 15 (2026), (Circular E), Employer's Tax Guide, What's New and section 7. States that the withholding rate on supplemental wages remains 22 percent, and 37 percent if supplemental wages paid to an employee during the calendar year exceed $1 million, and gives the two methods. The same publication gives the 2026 Social Security wage base of $184,500 and the 6.2 percent and 1.45 percent rates. Retrieved November 4, 2026.
IRS, Topic No. 751, Social Security and Medicare Withholding Rates. The 0.9 percent Additional Medicare Tax withholding on wages over $200,000 in a calendar year.

Last reviewed: November 4, 2026.