US Bonus Withholding Calculator
Estimate what remains from a separately identified 2026 bonus under the federal supplemental percentage method. See each federal and employee payroll withholding component, including wage-base thresholds.
This estimates selected withholding on one payment, not your final income tax, a guaranteed paycheck, or an employer quote. It does not calculate the aggregate method, W-4 adjustments, state-specific rules, benefits, retirement contributions or employer taxes.
Rules reviewed 28 September 2026 · US calendar year 2026
How the 2026 estimate is calculated
The optional federal percentage method can apply when supplemental wages are separately identified and the employer withheld federal income tax from regular wages in the current or immediately preceding year. This calculator assumes those conditions. Your employer may instead use the aggregate method. Confirm the method with payroll.
| Component | 2026 model |
|---|---|
| Federal supplemental percentage | 22% until this employer’s calendar-year supplemental wages exceed $1 million; 37% on the excess. |
| Employee Social Security | 6.2% on bonus wages still below the $184,500 wage base. |
| Employee Medicare | 1.45% on the bonus. |
| Additional Medicare withheld | 0.9% on wages this employer pays above $200,000 in the year. |
| State and local | Your own entered percentages applied to gross bonus; no jurisdiction is inferred. |
Prior wages mean wages from the same employer before this payment, including earlier bonuses. Prior supplemental wages are the subset used to determine whether the $1 million federal threshold has already been reached. Do not add the current bonus to either input. This simplified model assumes a single employer. IRS rules may combine supplemental wages from businesses under common control; ask payroll if that applies to you.
Worked examples
With $70,000 of wages already paid, a $5,000 bonus, no earlier supplemental pay and zero entered state/local withholding, the model estimates $1,100 federal, $310 Social Security and $72.50 Medicare. That leaves $3,517.50.
With $180,000 already paid and a $10,000 bonus, only $4,500 of the bonus remains below the 2026 Social Security wage base. The model estimates $279 Social Security, not $620.
If $995,000 of supplemental wages have already been paid by the employer, the next $10,000 bonus crosses the federal threshold: $5,000 at 22% and $5,000 at 37%, or $2,950 federal withholding.
What this calculator does not decide
Withholding is a payment toward tax. It is not the final tax liability on your return. The actual amount deposited may differ because of how payroll combines pay, W-4 elections, deductions, benefit costs, state and local rules, and rounding. This tool does not determine whether your plan owes you a bonus.
The federal rules and examples come from IRS Publication 15 (2026), section 7. The Social Security Administration’s 2026 contribution and benefit base is $184,500. Check current payroll guidance if you model a different tax year.
For a gross award determined from salary, use the gross bonus pay calculator. For a target net award using a single assumed rate, use the bonus gross-up calculator. This page answers a different question: estimated withholding on a known gross bonus under one stated US payroll method.
Questions about bonus withholding
Is a bonus always withheld at 22%?
No. The federal percentage method has conditions, the amount over $1 million of supplemental wages is withheld at 37%, and payroll may use an aggregate method. State and employee payroll withholding can add to the amount.
Does withholding equal the tax I ultimately owe?
No. Your final income tax is determined separately; federal withholding on this check is a payment toward it.
Why enter wages already paid this year?
They determine how much of this bonus remains below the 2026 Social Security wage base and whether the employer reaches the Additional Medicare withholding threshold.