Gross Up Calculator 2026
Enter a target net bonus to estimate the gross payment needed after flat-method federal and employee payroll withholding. Use wages already paid before this bonus; add state/local withholding only if you know the applicable rate.
Bonus gross-up inputs
Taxable wages paid by this employer before this bonus, including earlier bonuses.
Use Medicare wages from payroll; this base can differ from Social Security wages.
Include prior bonuses and other supplemental wages from this employer and businesses under common control.
Optional flat percentage supplied by payroll. 0% excludes state/local withholding; it does not mean your state has no tax.
Confirm the method with payroll. Ordinary salary withholding, aggregate-method bonuses, benefit deductions, and employer payroll taxes are not modeled.
Estimated gross bonus needed
$1,421.47
Target net $1,000.00 · calculated net $1,000.01
- Federal supplemental withholding
- $312.72
- Employee Social Security
- $88.13
- Employee Medicare
- $20.61
- Additional Medicare withholding
- $0.00
- State/local withholding assumption
- $0.00
- Total employee withholding
- $421.46
- Net bonus after modeled withholding
- $1,000.01
Tax lines round to cents. The calculated net may exceed the target slightly ($0.01). This is a withholding estimate, not a final tax or refund calculation.
How to gross up a bonus
- Choose the employee's target net amount, rather than the employer's total budget.
- Check the supplemental withholding method and enter prior taxable wages.
- Review each withholding line and verify any state/local rate with payroll.
- Compare gross minus withholding with the target. A single combined rate works only when the payment crosses no rate threshold.
For example, a $1,000 net bonus with 22% federal, 6.2% Social Security, and 1.45% Medicare withholding requires approximately $1,421.47 gross, before state/local withholding. This assumes the entire payment stays below the Social Security limit and Medicare threshold. The calculator changes the applicable portion when those thresholds are crossed.
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Frequently asked questions
What is a gross up calculator?
A gross up calculator works backward from the net amount you want to receive. This tool estimates a separately identified bonus under the flat supplemental withholding method, then shows the gross payment and employee tax lines. It does not calculate an ordinary salary paycheck or the employer's full cost.
Can I divide net pay by one minus the tax rate?
Only when every applicable rate stays constant across the payment. This tool solves the payment across the Social Security wage limit, Additional Medicare withholding threshold, and supplemental-wage threshold. Each displayed tax line is rounded to cents and reconciled to net pay.
When can a bonus use 22% federal withholding?
The flat method is available for separately identified supplemental wages when federal income tax was withheld from regular wages in the current or preceding calendar year. Payroll may choose the aggregate method instead. This tool does not implement that method. The portion of annual supplemental wages above $1 million has mandatory 37% withholding.
Why do you ask for YTD wages instead of annual salary?
Employee Social Security withholding applies only to the remaining 2026 wage-base room. Employers start Additional Medicare withholding after Medicare wages they have paid exceed $200,000, regardless of filing status. Enter wages already paid before this bonus, including prior bonuses; projected wages for later in the year do not belong here.
Does this include state and local taxes?
Federal income and employee Social Security and Medicare withholding are modeled. You may add a flat state/local employee withholding percentage supplied by payroll; zero excludes those amounts. This is a user assumption, not a verified state payroll calculation. Other deductions and employer payroll taxes are excluded.
Is gross-up withholding my final tax bill?
No. Bonus withholding is a payment toward tax. Your final return includes other income, deductions, credits, and filing status. The result does not predict a refund or balance due.
Sources and calculation scope
Rules checked October 5, 2026: IRS Publication 15 (2026), sections 7 and 9 and IRS Social Security and Medicare withholding rates. The 2026 Social Security wage base is $184,500. Employer Additional Medicare withholding uses $200,000; filing-status thresholds on the final return can differ. The user-supplied state/local rate is not an official state calculation.