What grossing up means
To gross up a payment is to raise it by enough to cover the taxes on it, so the person receives a set amount after withholding. Employers do it for a spot bonus meant to be "$500 in your pocket", for an award or a relocation payment, or when an employment agreement promises a net figure. The added amount is itself taxable wages, so the gross-up must cover the tax on the tax as well. That is why you cannot simply add the tax rate on top.
Why adding the tax on top falls short
Take a $1,000 net bonus for an employee under the Social Security wage base, in a state with no income tax. Withholding on a bonus is 22% federal under the flat-rate method plus 7.65% Social Security and Medicare, 29.65% in all. Adding 29.65% to $1,000 gives $1,296.50, but 29.65% of $1,296.50 is $384.41, which leaves only $912.09. The right gross is the net divided by what is left after tax: $1,000 ÷ (1 − 0.2965) = $1,421.47. Withholding on that is $312.72 federal, $88.13 Social Security and $20.61 Medicare, which leaves the $1,000.
Grossing up a regular paycheck
A regular paycheck is harder, because income tax is not one flat rate: the standard deduction and the brackets make the rate depend on the amount. The calculator therefore searches for the gross: it tries an amount, runs the same paycheck routine as the paycheck calculator, and narrows in until the take-home matches to the cent. For example, a single filer paid every two weeks who wants $2,000 of take-home in 2026, with no state wage tax, needs a gross paycheck of about $2,384.76, or $62,004 a year. The result table runs that gross forward, so you can check that it lands on your number.
Things to know before you promise a net amount
- Withholding is not the final tax. A gross-up covers what is withheld. The employee's actual tax is settled on their return, and a bonus withheld at 22% may produce a refund for someone in the 12% bracket or a balance due for someone in the 32% bracket.
- The Social Security wage base matters. Once an employee's wages for the year pass the wage base, 6.2% Social Security stops, and a gross-up needs less. That is why the bonus mode asks for the regular salary.
- Bonuses over $1 million are withheld at 37% on the excess, and the calculator applies it.
- State withholding on bonuses varies: many states set their own flat supplemental rate. Enter your state's rate to include it.
To see what a bonus already set in gross terms leaves after tax, use the bonus tax calculator.