Wisconsin Bonus Calculator
Bonus Details
Federal W-4 Settings
Wisconsin Withholding (Form WT-4)
Deductions (Per Regular Paycheck)
Year-To-Date Data (Optional, Improves Accuracy)
Your Bonus Estimate
- Bonuses are not taxed at a special bonus rate when you file. They are ordinary income taxed at your regular marginal rate.
- The 22 percent federal flat rate is simply a withholding method employers use on supplemental wages paid separately. It is not a tax rate.
- Wisconsin uses a unique tiered flat rate for supplemental wages based on total annual gross wages: 3.54 percent under $12,760, 4.65 percent from $12,760 to $25,520, 5.3 percent from $25,520 to $280,950, and 7.65 percent above $280,950.
- The aggregate method is also permitted: your bonus is combined with regular wages, the Wisconsin standard deduction is applied, and Wisconsin graduated brackets (3.50 percent to 7.65 percent) determine the bonus share of withholding.
- Wisconsin has no local income tax on wages.
- When you file your return, your total annual income determines your true liability. Over-withholding on the bonus becomes part of your refund. Under-withholding becomes tax due.
- Gross-up mode solves for the gross bonus your employer must pay so your take-home equals the target you enter.
What Is a Wisconsin Bonus Calculator?
A Wisconsin Bonus Calculator estimates the taxes withheld from an employee bonus and the amount left after withholding. It combines federal supplemental wage rules, Wisconsin supplemental withholding rules, Social Security, Medicare, W-4 settings, WT-4 settings, regular salary, pay frequency, deductions, and optional year-to-date payroll information.
The calculator can estimate take-home pay from a known gross bonus or work backward from a desired take-home amount. It also shows the selected federal and Wisconsin withholding methods, alternative-method estimates, full-pay-period results, annual federal and Wisconsin income tax estimates, and a projected refund or amount due based on the information entered.
For a Wisconsin employee, the calculator answers a common question: how much of my bonus will I actually receive? It subtracts estimated federal withholding, Wisconsin withholding, Social Security, Medicare, and any applicable Additional Medicare Tax from the gross bonus. The result is an estimated bonus take-home amount, not your final tax liability.
How the Wisconsin Bonus Calculator Works
The calculator starts with the bonus amount and calculates each type of withholding separately. The basic bonus take-home calculation is:
- N is estimated bonus take-home pay.
- B is the gross bonus.
- F is federal income tax withheld from the bonus.
- S is Social Security tax attributable to the bonus.
- M is the 1.45 percent Medicare tax on the bonus.
- A is any 0.9 percent Additional Medicare Tax attributable to the bonus.
- W is Wisconsin income tax withheld from the bonus.
Under the federal flat method, the calculator withholds 22 percent on supplemental wages until cumulative federal supplemental wages reach $1,000,000. Any portion above that threshold is withheld at 37 percent. Prior year-to-date supplemental wages are included when deciding whether the bonus crosses the threshold.
Under the federal aggregate method, the calculator adds the bonus to the current regular paycheck, annualizes the taxable wages, and applies its 2025 federal brackets and W-4 adjustments. Bonus withholding is the difference between withholding on the combined check and withholding on regular wages alone.
For Wisconsin's flat method, the code chooses a supplemental rate from total annual gross salary plus the bonus. The rates are 3.54 percent below $12,760, 4.65 percent from $12,760 to below $25,520, 5.3 percent from $25,520 to below $280,950, and 7.65 percent at $280,950 or more. The aggregate method instead applies the calculator's Wisconsin standard deduction and graduated brackets.
Social Security is calculated at 6.2 percent, but only up to the calculator's 2025 wage base of $176,100. Prior year-to-date Social Security wages can reduce how much of the current regular paycheck and bonus remain subject to that tax. Medicare is 1.45 percent without a wage cap. The calculator also applies 0.9 percent Additional Medicare withholding once year-to-date Medicare wages plus current wages exceed $200,000.
Worked Example
Assume a $75,000 base salary, a $5,000 gross bonus, biweekly pay, married filing jointly, no deductions or W-4 adjustments, no prior year-to-date wages, and the flat federal and Wisconsin methods.
- Federal bonus withholding is 22 percent of $5,000, or $1,100.
- Social Security is 6.2 percent of $5,000, or $310.
- Medicare is 1.45 percent of $5,000, or $72.50.
- Additional Medicare withholding is $0 because the calculator's $200,000 threshold is not reached.
- Total annual gross salary plus bonus is $80,000, so the Wisconsin flat rate is 5.3 percent. Wisconsin withholding is $265.
- Total bonus withholding is $1,747.50. Estimated bonus take-home pay is $3,252.50, with an effective withholding rate of 34.95 percent.
This example assumes the entered payroll information matches the employee's actual situation. Year-to-date wages can materially change Social Security and Additional Medicare withholding.
How to Use the Wisconsin Bonus Calculator: Step by Step
- Choose Estimate take-home from a bonus amount if you know the gross bonus. Choose Gross-up if you know the net amount you want to receive.
- Enter the bonus amount or desired net bonus, then enter your base annual salary excluding the bonus.
- Select your federal bonus withholding method, Wisconsin bonus withholding method, pay frequency, federal filing status, and Wisconsin filing status.
- Enter applicable federal W-4 settings. These include Step 2, dependent credits, other annual income, annual deductions, and extra federal withholding per paycheck.
- Enter any extra Wisconsin withholding and your pre-tax and post-tax deductions per regular paycheck. The calculator treats pre-tax deductions as reducing federal and Wisconsin income-tax wages, but not Social Security or Medicare wages.
- If available, enter prior year-to-date Social Security wages, Medicare wages, federal supplemental wages, pay periods already received, federal withholding, and Wisconsin withholding.
- Check the acknowledgment that the calculation estimates withholding rather than final tax liability, then calculate the result.
The main result is your estimated bonus take-home amount and effective withholding rate. The calculator also separates federal, Wisconsin, Social Security, Medicare, and Additional Medicare withholding. Its full-pay-period section combines regular wages with the bonus, while the annual snapshot estimates income taxes and projected withholding using the values you supplied.
What Your Wisconsin Bonus Calculator Result Means
Bonus Take-Home Versus Final Tax
The bonus take-home result shows what remains after the calculator's estimated payroll withholding. It does not mean your bonus is taxed at that exact rate when you file your income tax return. Federal and Wisconsin bonus withholding are payment methods used during the year. Your eventual income tax liability depends on your full-year tax situation.
| Calculator Item | How the Code Handles It |
|---|---|
| Federal flat method | 22% on supplemental wages up to the cumulative $1,000,000 threshold and 37% above it |
| Federal aggregate method | Compares withholding on regular wages plus bonus with withholding on regular wages alone |
| Wisconsin flat method | Uses a tiered supplemental rate based on base annual salary plus the bonus |
| Wisconsin aggregate method | Uses annualized wages, the calculator's Wisconsin standard deduction, and graduated brackets |
| Social Security | 6.2% subject to a $176,100 2025 wage base |
| Medicare | 1.45% of regular wages and bonus |
| Additional Medicare | 0.9% on wages exceeding the calculator's $200,000 threshold |
Why Year-to-Date Information Matters
Year-to-date data can change several results. Prior Social Security wages determine how much room remains under the wage base. Prior Medicare wages affect Additional Medicare withholding. Prior federal supplemental wages determine whether the bonus crosses the $1,000,000 supplemental-wage threshold. Prior withholding and completed pay periods also affect the projected refund or amount due shown in the annual snapshot.
Important Limitations
This calculator is based on the 2025 tax settings coded into the tool. It estimates payroll withholding and annual income taxes using the entered values and its built-in assumptions. Actual payroll or tax results can differ because of employer payroll systems, other income, deductions, credits, benefits, tax-law changes, or information not represented by the calculator. The results are not tax, payroll, financial, or legal advice.
Bonus Calculators for All 50 U.S. States
Frequently Asked Questions
How much tax is withheld from a bonus in Wisconsin?
The amount depends on the withholding methods and payroll details you enter. The calculator can apply federal flat or aggregate withholding and Wisconsin flat or aggregate withholding. It also includes Social Security, Medicare, and Additional Medicare withholding when applicable, so the total percentage withheld can be higher than either income-tax rate alone.
What is the Wisconsin bonus withholding rate?
Under this calculator's flat Wisconsin method, the rate is 3.54%, 4.65%, 5.3%, or 7.65%, depending on base annual salary plus the bonus. The code moves to the next tier at $12,760, $25,520, and $280,950. Users can also select the calculator's aggregate Wisconsin withholding method.
Is a bonus taxed at 22 percent federally?
Not necessarily. In this calculator, 22 percent is the federal flat supplemental withholding rate on qualifying supplemental wages below the cumulative $1,000,000 threshold. It is a withholding method, not the employee's final income tax rate. The calculator also offers an aggregate federal method based on annualized paycheck withholding.
Does the Wisconsin Bonus Calculator include Social Security and Medicare?
Yes. The calculator includes 6.2 percent Social Security withholding up to its 2025 wage base of $176,100 and 1.45 percent Medicare withholding. It also calculates 0.9 percent Additional Medicare withholding on applicable wages above $200,000. Optional year-to-date wage inputs help determine when these thresholds are reached.
What is the difference between flat and aggregate bonus withholding?
The flat methods apply a supplemental withholding rate directly to the bonus. The aggregate methods combine the bonus with regular wages and calculate paycheck withholding using annualized income-tax rules. The calculator then subtracts regular-pay withholding to isolate the bonus portion. It displays an estimate for the alternative method for comparison.
How does the gross-up bonus calculator work?
Gross-up mode starts with the desired after-withholding bonus amount and searches for the gross bonus needed to reach that target. The code repeatedly recalculates withholding until it finds a gross amount whose estimated net bonus meets the requested take-home amount. The resulting required gross bonus is rounded upward to the nearest cent.
How accurate is the Wisconsin Bonus Calculator?
The result is an estimate based on the 2025 federal and Wisconsin rules built into the calculator and the information you enter. Accuracy improves when year-to-date payroll data is included. Actual withholding can still differ because of payroll practices, tax circumstances, later income, deductions, credits, and tax rules outside the calculator.