This calculator helps estimate the net amount you receive from a bonus after typical tax withholdings and payroll deductions, and it optionally estimates the employer's additional payroll tax cost. Select the withholding method used by payroll (supplemental flat-rate or aggregated with wages), enter federal/state rates and payroll tax percentages, and the tool returns a clear breakdown.
In many payroll systems, bonuses are treated as supplemental wages and may be withheld at a flat supplemental rate for federal tax purposes. Alternatively, payroll can aggregate the bonus with regular wages and calculate withholding at the employee's marginal rate. Additionally, payroll (Social Security and Medicare) still applies to bonuses.
The core formulas used by this calculator are:
For a gross bonus $B$ with supplemental withholding rate $r_s$ (as a decimal), federal and state rates $r_f, r_{st}$ (decimals), and payroll rates for Social Security $r_{ss}$ and Medicare $r_{med}$ (decimals):
Supplemental withholding method:
$$\text{TaxWithheld} = B \times r_s$$
Aggregate withholding method (approximate):
$$\text{TaxWithheld} \approx B \times (r_f + r_{st})$$
Payroll taxes (employee-side):
$$\text{PayrollTaxes} = B \times (r_{ss} + r_{med})$$
Net bonus received:
$$\text{Net} = B - \text{TaxWithheld} - \text{PayrollTaxes} - \text{OtherWithholdings}$$
Example: $B = \$10{,}000$, supplemental $r_s=22\%$, state $r_{st}=4\%$, Social Security $r_{ss}=6.2\%$, Medicare $r_{med}=1.45\%$.
Using supplemental withholding:
$$\text{TaxWithheld} = 10{,}000 \times 0.22 = \$2{,}200$$
$$\text{PayrollTaxes} = 10{,}000 \times (0.062 + 0.0145) = \$765$$
$$\text{Net} = 10{,}000 - 2{,}200 - 765 = \$7{,}035$$
| Scenario | Withholding Method | Tax Withheld | Payroll Taxes | Net Received |
|---|---|---|---|---|
| $10,000 Bonus | Supplemental (22%) | $2,200 | $765 | $7,035 |
| $10,000 Bonus | Aggregate (Marginal 24% + State 4%) | $2,800 | $765 | $6,435 |
Supplemental withholding is a fixed percentage applied to bonuses and other supplemental wages for federal tax withholding. Employers often use this for bonuses because it simplifies payroll processing and ensures tax is withheld at a standard rate (commonly 22% in the US).
Withholding is an estimate toward your final tax liability. When you file taxes, your actual income tax is calculated and you'll either owe more or receive a refund depending on your total tax situation for the year.
Yes. Employers typically pay employer-side payroll taxes (Social Security, Medicare, state unemployment insurance, etc.) which increase the total employer cost above the gross bonus. Our calculator estimates employer cost using a configurable employer payroll tax percentage.
The calculator is generic — you can input local tax and payroll percentages to approximate net bonus under other jurisdictions. For precise obligations, consult your payroll department or a tax professional.