How to use the bonus gross up calculator
- Enter the take-home amount the person should receive after withholding.
- Enter the flat withholding rate. The 25% shown is an example, not a rate to rely on. Use the combined flat percent your payroll takes from this payment.
- Open More options to add a second flat percent that is taken from the same payment.
- Read the headline for the gross bonus, then check the withholding, the take-home check and the comparison with the shortcut of adding the percent.
Formula
gross = take-home / (1 - rate)
withheld = gross x rate, rounded to the cent (half up)
take-home = gross - withheld
The page searches in whole cents for the smallest gross whose take-home is at least the amount you asked for, so rounding never leaves the person a cent short. The gross-up factor is 1 / (1 - rate).
A $1,000 take-home at 25%
Gross = $1,000 / (1 - 0.25) = $1,333.33. Withholding 25% of $1,333.33 is $333.3325, which rounds to $333.33, and $1,333.33 - $333.33 = $1,000.00. A gross one cent lower would leave $999.99.
The common shortcut of adding 25% to $1,000 gives $1,250, but 25% of $1,250 is $312.50, so only $937.50 is left, $62.50 short. For two percents of 22.5% and 5.65% (combined 28.15%) on a $2,500 take-home, the gross is $3,479.47 with $979.47 withheld.
Why you cannot just add the percent
The withholding is taken from the gross, not from the take-home. If you want $1,000 left after 25% is removed, the gross must be the amount that is still $1,000 after losing a quarter, which is $1,000 divided by 0.75, not $1,000 times 1.25. The gap between the two grows with the rate.
The factor 1 / (1 - rate) is the multiplier to remember. At a combined 25% it is 1.3333, at 40% it is 1.6667, and it climbs steeply as the rate nears 100%. The page refuses a combined rate of 100% or more because no gross could leave anything.
What this page leaves out
Real payroll can apply several rates, caps, tax tables and benefit rules to the same payment, and a bigger gross may change other deductions. This page models one flat percent taken from the payment. It builds in no rates, so confirm the figure with your payroll provider. For related pay tools, see the Gross Pay Calculator and the Paycheck Savings Split Calculator.
Assumptions and limits
- One combined flat percent is taken from the payment. No rate is built in. The 25% in the example is only an example.
- Percentages may have up to three decimals, and the take-home amount up to two decimals.
- The combined percent must be below 100.
- This is arithmetic, not payroll or tax advice. Caps, brackets and other deductions are not modeled.
Frequently asked questions
How do you gross up a bonus?
Divide the take-home you want by one minus the withholding rate as a decimal. To net $1,000 at 25%, divide by 0.75 to get $1,333.33. The page then rounds to the cent so the take-home is at least the amount you want.
Why is adding the percentage to the net amount wrong?
Because the percent applies to the larger gross, not to the net. Adding 25% to $1,000 gives $1,250, but withholding 25% of that leaves $937.50. Dividing by 0.75 is what gets the full $1,000.
What withholding rate should I enter?
Enter the combined flat percent your payroll will take from this particular payment. This page builds in no rates and cannot know yours, so check with your payroll provider or accountant.
Can the gross-up leave a cent more than I asked for?
Sometimes. Because the withholding is rounded to the cent, no gross may land on exactly the target. The page chooses the smallest gross that gives at least your target, so the take-home check can be one cent above it.