Supplemental withholding gap
Compare federal 22% / 37% supplemental withholding against your actual marginal rate.
Supplemental withholding gap
Federal supplemental withholding on RSUs is flat at 22%, rising to 37% above $1M YTD. Here's how that lines up against your actual marginal rate.
How to read the result
The 22% flat supplemental rate assumes you are a middle-bracket earner. For tech employees above $250k in ordinary income, 22% leaves a large gap at filing. This calculator shows exactly how much.
This tool is educational. It uses 2025 single-filer federal brackets, a simplified state-tax model, and does not substitute for a CPA review of your specific facts. For a second set of eyes on a meaningful event, match with a fiduciary advisor who routinely works with equity compensation.
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