Bonus paycheck calculator
Bonuses are usually taxed at the IRS supplemental rate of 22% federal (37% on amounts over $1M cumulative supplemental wages). Plus FICA, state, and local. The withholding rate is not your final tax rate.
Estimated bonus paycheck
| Federal (22%/37% supplemental) | −$1100.00 |
| Social Security | −$310.00 |
| Medicare | −$72.50 |
| Estimated total withheld | −$1482.50 |
| Estimated net bonus | $3517.50 |
| Effective withholding rate | 29.6% |
- Bonuses are usually treated as supplemental wages. The IRS allows the flat method (22% federal, 37% over $1M cumulative supplemental wages) or the aggregate method.
- The withholding rate is not your final tax rate. Your true liability is settled when you file.
- State: CA estimated $0.00 withheld at the supplemental rate.
Two methods employers use
- Flat method: 22% federal flat rate (37% over $1M YTD supplemental wages). Simpler — used when bonus is paid separately from regular wages.
- Aggregate method: Bonus is added to your most recent regular paycheck and withheld using normal W-4 tables. Often results in higher temporary withholding because the lump sum looks like a much higher annual rate.
Why your "bonus tax" feels brutal
The flat 22% on top of FICA (7.65%) plus state and local can take 30–45% of the gross bonus before it hits your account. This is withholding — not your final tax. If your effective annual tax rate is lower than the supplemental rate, the difference comes back as a refund (or reduces what you owe).
Official sources
- IRS Topic 751 — Social Security and Medicare Withholding Rates — IRS · 2025 · last verified 2025-04-01
- IRS — Supplemental wage withholding (Pub. 15 §7) — IRS · 2025 · last verified 2025-04-01
Common questions
Why was my bonus taxed so much?▾
Bonuses are usually treated as supplemental wages and withheld at a flat 22% federal rate (37% over $1M), plus FICA, state, and local. The withholding rate is not your final tax rate — your true liability is settled when you file your return.
Will I get some of that bonus tax back?▾
Possibly — if your effective annual tax rate is lower than the supplemental withholding rate, the difference comes back as a refund (or reduces what you owe).