A bonus feels like it's taxed harder than your salary — but it isn't. The IRS calls bonuses “supplemental wages,” and most employers withhold a flat 22% federal rate on them, then add Social Security, Medicare, and state tax. That upfront withholding can swallow 30–40% of the check. Your actual tax, though, is your normal marginal rate on the extra income — which this calculator finds by comparing your yearly take-home with and without the bonus. If too much was withheld, you get the difference back when you file.
