Calculate taxes on bonus pay using the flat 22% federal rate (37% over $1M) or aggregate method. Includes state supplemental wage tax estimates.
Bonuses and other supplemental wages are subject to special federal tax withholding rules. Employers can choose between two IRS-approved methods: the flat percentage method, which withholds 22% on the first $1 million and 37% on amounts exceeding $1 million, or the aggregate method, which combines the bonus with regular pay and calculates withholding on the total as if it were a single payment.
The method chosen significantly affects how much tax is withheld from the bonus check. The flat method is simpler and often preferred for its predictability, while the aggregate method may withhold more or less depending on the employee's regular pay and tax bracket. Neither method changes the total tax owed—the difference is reconciled when filing the annual tax return.
This Bonus Tax Calculator estimates the net bonus under both methods. Enter your bonus amount, regular pay, filing status, and state supplemental rate to compare take-home amounts. Whether you're an employee planning how to spend a year-end bonus or an HR professional choosing the withholding method, this tool provides the clarity you need.
Employees often experience sticker shock when they see how much tax is withheld from a bonus. This calculator shows the exact withholding under both IRS methods Having a precise figure at your fingertips empowers better planning and more confident decisions. Manual calculations are error-prone and time-consuming; this tool delivers verified results in seconds so you can focus on strategy., plus state and FICA taxes. Understanding the breakdown helps employees plan accurately and reduces complaints about "missing" bonus money.
Flat Method: Federal Tax = Bonus × 22% (37% on amounts over $1,000,000) FICA = Bonus × 7.65% (subject to wage base limits) State Tax = Bonus × State Supplemental Rate Net Bonus = Bonus − Federal Tax − State Tax − FICA
Result: $6,735 net bonus
Federal flat rate: $10,000 × 22% = $2,200. State: $10,000 × 5% = $500. Social Security: $10,000 × 6.2% = $620. Medicare: $10,000 × 1.45% = $145. Total tax: $3,465. Net bonus: $10,000 − $3,465 = $6,535.
Most payroll software defaults to the flat method for simplicity. The employer withholds exactly 22% in federal tax (plus FICA and state), making the calculation straightforward. The aggregate method is more complex: it temporarily adds the bonus to the most recent regular paycheck, calculates total withholding using standard tax tables, then subtracts the already-withheld amount on regular pay.
Regardless of which withholding method the employer uses, the employee's actual tax liability is determined on their annual tax return. If too much was withheld (common with the aggregate method), the employee receives a refund. If too little was withheld, additional tax is owed. Adjust W-4 allowances proactively if you expect a large bonus.
Strategies to increase the net bonus include maximizing pre-tax 401(k) contributions, making HSA contributions, and timing the bonus payment to a period where you've already exceeded the Social Security wage base. Consult with a tax advisor to align bonus timing with your overall tax strategy.
The IRS flat rate for supplemental wage withholding is 22% on the first $1 million in bonus/supplemental wages per calendar year. Any amount exceeding $1 million is withheld at 37%, the top marginal rate.
The aggregate method combines the bonus with the most recent regular payroll and calculates federal withholding on the total as if it were a single regular payment. It then subtracts what was already withheld on the regular pay to determine the bonus withholding. This can result in higher or lower withholding than the flat method.
Neither method changes total tax liability—both affect only the timing of tax payments. The flat method provides predictable withholding. The aggregate method may over-withhold for lower earners but more closely approximates actual tax for high earners. The difference resolves when filing your annual return.
Bonuses are taxed at the same rates as regular income on your annual return. The difference is in withholding: bonuses can use the flat 22% rate or aggregate method, while regular pay uses standard W-4-based withholding tables. Final tax liability is identical regardless of withholding method.
Yes. Social Security tax (6.2%) applies to bonuses up to the annual wage base limit ($168,600 for 2024). Medicare (1.45%) applies to all bonus amounts. The additional 0.9% Medicare surtax applies if total wages exceed $200,000.
If your year-to-date wages already exceed the Social Security wage base, no additional Social Security tax (6.2%) is withheld from the bonus. Medicare (1.45%) continues to apply with no cap. This increases your net bonus for bonuses paid late in the year.
Most states with income tax apply a supplemental wage rate to bonuses. Rates vary: California uses standard withholding tables, New York applies 11.7%, and others use flat supplemental rates. Nine states have no income tax.
Yes. If your employer allows it, you can elect to contribute part or all of a bonus to your pre-tax 401(k), reducing current taxable income. The contribution must not exceed the annual 401(k) limit ($23,000 for 2024 plus $7,500 catch-up if 50+).