Bonus and Supplemental Wage Tax Calculator
Compare federal flat supplemental withholding with an aggregate-method estimate and payroll taxes.
Official rules and scope
Tax year 2026. Rules reviewed September 10, 2026. Results depend entirely on entered assumptions and omit state/local taxes and specialized return rules unless explicitly shown.
IRS Publication 15-T · IRS Publication 505 · IRS Publication 15 · IRS Revenue Procedure 2025-32
How bonus withholding works
When separately identified supplemental wages do not exceed $1 million, an employer that meets the regular-wage withholding condition may use a flat 22% federal rate or the aggregate method. Supplemental wages above $1 million are withheld at 37%.
Bonuses are also generally subject to Social Security and Medicare withholding. Additional Medicare withholding starts when an employer pays an employee more than $200,000 during the year.
Withholding is a prepayment and may differ from final tax on the return.