Supplemental Wage Withholding Calculator

Employers may withhold on RSU vesting and bonuses using optional flat rates (commonly 22% or 37% for large payments) or by aggregating with regular wages. Compare flat withholding to your marginal tax rate to spot a potential April balance due.

Supplemental wages
22% vs 37%
RSU withholding

Inputs

Enter one supplemental payment (e.g., annual RSU vest income). Marginal rate is your combined federal estimate.

Optional flat rate for comparison

Go deeper on the rules and planning ideas behind this calculator.