Bonus Tax Calculator

The Bonus Tax Calculator computes the exact amount of taxes withheld from a supplemental wage payment (such as a year-end bonus) and reveals the net amount you will actually take home.

How Bonus Tax Withholding Works

In the United States, the IRS considers bonuses as "supplemental wages." They are taxed differently than your regular paycheck. Employers typically use one of two methods to calculate federal income tax withholding on bonuses, but the most common is the Percentage Method.

The calculator uses the Percentage Method, which taxes bonuses up to $1 million at a flat federal rate, plus standard payroll taxes (FICA) and any applicable state taxes.

The Calculation Logic

To determine your net bonus, the calculator applies the following deductions:

1. Federal Supplemental Tax: A flat 22% rate applied to the entire bonus amount (for bonuses under $1 million).
2. FICA Tax (Social Security & Medicare): A combined flat rate of 7.65% (6.2% for Social Security and 1.45% for Medicare).
3. State Tax: Calculated based on the specific state tax rate percentage you provide.

$\text{Net Bonus} = \text{Gross Bonus} - (\text{Federal Tax} + \text{FICA Tax} + \text{State Tax})$

Input Parameters

| Parameter | Description | |---|---| | Bonus Amount | The total gross amount of the bonus awarded before any taxes are deducted. | | State Tax Rate (%) | Your state's specific supplemental tax rate or standard income tax rate. |

Worked Example

Scenario: You receive a $10,000 year-end bonus. You live in a state with a 5% state tax rate.

Calculation Steps:

1. Federal Tax: 10,000 \times 22\% = \2,200$
2. FICA Tax: 10,000 \times 7.65\% = \765$
3. State Tax: 10,000 \times 5\% = \500$
4. Total Tax Withheld: \2,200 + $765 + $500 = $3,465$
5. Net Bonus: \10,000 - $3,465 = $6,535$

Result: From a $10,000 gross bonus, your actual take-home pay will be **$6,535**.

Limitations and Assumptions

• Federal Flat Rate Only: This calculator assumes the standard Percentage Method (22% flat rate) for supplemental wages. If your employer uses the Aggregate Method (combining your bonus with your regular pay and taxing it based on your W-4), your actual withholding will differ.
• **Bonuses Over $1 Million:** If your supplemental wages exceed$1 million for the year, the amount over $1 million is subject to a higher mandatory federal withholding rate (37$1 million+ bracket.
• Local Taxes Excluded: The calculation only accounts for federal and state taxes. It does not include local city or county taxes, or pre-tax deductions like 401(k) contributions from bonuses.
• FICA Wage Base Limit: The Social Security portion of FICA (6.2%) only applies up to a certain annual wage limit. If your total income for the year exceeds this cap, you will only pay the Medicare portion (1.45%) on the excess. This calculator assumes you have not hit the Social Security cap.