Bonus Tax Calculator
Estimate how much of your bonus you may take home after federal withholding, state tax, Social Security, Medicare, and optional 401(k) deductions.
Bonus Tax Calculator
Calculation Results
Estimate Your Take-Home Bonus After Taxes
This Bonus Tax Calculator helps estimate how much of a bonus, signing bonus, commission, RSU vesting income, overtime payment, severance payment, or other supplemental wage payment you may keep after federal income tax withholding, state income tax, Social Security, Medicare, Additional Medicare Tax, and optional 401(k) contributions.
The calculator compares the common federal supplemental wage flat withholding method with an estimated aggregate tax method and an estimated actual tax burden. It is designed for U.S. taxpayers and uses 2026 federal tax assumptions, including the supplemental wage withholding rate, Social Security wage base, standard deduction amounts, and 401(k) employee contribution limit.
What Are Supplemental Wages?
The IRS generally refers to compensation paid in addition to regular wages as supplemental wages. Supplemental wages may include:
- Year-end bonuses
- Performance bonuses
- Signing bonuses
- RSU vesting income
- Commissions
- Overtime pay
- Back pay
- Severance pay
- Awards, prizes, and certain incentive payments
Supplemental wages are generally taxed as ordinary wage income, but the key difference is the withholding method. Employers may withhold federal income tax using a flat supplemental wage rate or by combining the supplemental wages with regular wages under an aggregate method. This means your bonus withholding may not equal your final tax liability when you file your return.
Flat Method vs Aggregate Method
Flat Method
The flat method is one of the most common ways employers withhold federal income tax from bonuses and other supplemental wages. Under this method, federal tax is generally withheld at 22% for supplemental wages up to $1,000,000 during the year.
The advantage of the flat method is simplicity. However, the 22% withholding rate may be too low for high-income employees whose actual marginal federal tax rate is 24%, 32%, 35%, or 37%. In that case, the employee may owe additional federal tax when filing a tax return.
Aggregate Method
Under the aggregate method, the employer combines the bonus with regular wages and calculates withholding as if the combined amount were part of a regular payroll payment. The employer then subtracts the withholding that would apply to the regular wages alone.
The aggregate method may produce higher withholding, especially for large bonuses, but it may also be closer to the employee’s actual tax burden and reduce the chance of a large tax bill at filing.
2026 Bonus Tax Key Numbers
| Item | 2026 Amount or Rate | Notes |
|---|---|---|
| Federal supplemental wage withholding rate | 22% | Generally applies to supplemental wages up to $1,000,000 |
| Federal withholding rate over $1,000,000 | 37% | Applies to supplemental wages above the annual $1,000,000 threshold |
| Social Security wage base | $184,500 | Wages above this amount are not subject to the 6.2% employee Social Security tax |
| Medicare tax | 1.45% | No wage cap |
| Additional Medicare Tax | 0.9% | Applies above income thresholds such as $200,000 single / $250,000 MFJ |
| Standard deduction | $16,100 / $32,200 | Single / married filing jointly assumptions used by this calculator |
| 401(k) employee elective deferral limit | $24,500 | Catch-up contributions may apply for eligible taxpayers age 50 or older |
| Underpayment penalty interest | Variable | IRS rates can change quarterly |
Why Your Bonus Withholding May Not Equal Your Final Tax
Bonus withholding is not always the same as your final tax liability. Withholding is only a prepayment of tax. Your final tax depends on your total income, deductions, credits, filing status, state tax rules, payroll tax limits, and other factors.
If your employer withholds 22% federal tax on a bonus but your marginal tax rate is higher, you may owe additional tax when you file. If too much was withheld, you may receive a refund.
References
For official tax guidance, review the following government resources:
- IRS Publication 15, Employer's Tax Guide
- IRS Publication 15-T, Federal Income Tax Withholding Methods
- IRS Tax Topic No. 560, Additional Medicare Tax
- Social Security Administration Contribution and Benefit Base
- IRS 401(k) Plan Information
Disclaimer
This calculator is for general educational and informational purposes only. It provides estimates based on the inputs and assumptions shown on this page and should not be treated as tax, legal, payroll, accounting, or financial advice.
Actual withholding and final tax liability may differ depending on your employer’s payroll system, W-4 settings, state and local tax rules, deductions, credits, pre-tax benefits, retirement contributions, equity compensation, multiple employers, and other personal circumstances.
Please consult a qualified tax professional, CPA, payroll specialist, or financial advisor before making tax planning decisions.
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