Bonus Tax Calculator
Bonuses aren't taxed at a special rate — they're just withheld at a flat 22%. Here's what lands in your account, and whether that 22% over- or under-shoots the tax you'll actually owe in April.
What you keep
Net bonus in your account
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Federal withheld (22% flat)
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Social Security
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Medicare
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State
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To your 401(k)
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You keep
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The 22% is withholding, not tax
When a bonus is paid as a separate check, most employers use the IRS "percentage method": a flat 22% federal withholding (37% on any supplemental wages over $1M for the year). But your actual tax on the bonus is your marginal bracket. If you're in the 12% bracket, 22% over-withholds and the difference comes back in your refund. In the 32–37% brackets, 22% under-withholds and you'll owe the gap in April — worth knowing before you spend it.
FICA doesn't care that it's a bonus
Social Security (6.2%) and Medicare (1.45%) apply to a bonus like any other paycheck. Two wrinkles: Social Security stops once your year's wages pass the cap ($184,500 in 2026) — a late-year bonus after the cap skips it entirely — and an extra 0.9% Medicare kicks in on wages over $200k. Pre-tax 401(k) deferrals reduce income-tax withholding but never FICA.
The aggregate-method surprise
If your bonus is lumped into a regular paycheck instead of cut separately, the employer withholds as if you earned that much every period — which can grab far more than 22% up front. You get it back at filing, but it's the usual reason a bonus check looks shockingly small. Ask payroll which method they use.