Bonus Tax Calculator (2026)
What’s withheld from your bonus check isn’t what you actually owe on it — see both numbers side by side.
Used to correctly cap the Social Security portion if you’re near the annual wage base.
Bonus Tax Calculator
“Why did my bonus get taxed so much more than my paycheck?” is one of the most common payroll questions — and the honest answer is that it didn’t, not really. Bonuses aren’t taxed at a special higher rate; they’re ordinary income like everything else once you file. What actually happened is a withholding rule: employers are allowed to withhold a flat 22% from a bonus, regardless of your real tax bracket, which is often more than what you’ll actually owe on it. This calculator shows both numbers — what gets withheld today, and what the bonus really adds to your 2026 tax bill — side by side.
The Flat 22% Rate, Explained
When a bonus is paid separately from a regular paycheck (or clearly identified as supplemental pay even if combined), the IRS lets employers withhold a flat 22% federal rate on top of standard FICA — Social Security (6.2%, up to the $184,500 2026 wage base) and Medicare (1.45%, plus 0.9% more above $200,000/$250,000 depending on filing status). If total supplemental wages for the year exceed $1 million, everything above that is withheld at a mandatory 37% instead. None of this is your real tax rate — it’s just what gets taken out of the check today, reconciled against your actual liability when you file.
What the Bonus Actually Costs You
Your real tax cost isn’t 22% — it’s whatever your marginal rate is on that slice of income, once it’s stacked on top of your regular salary. This calculator computes your federal tax with the bonus included and without it, and the difference is what the bonus genuinely adds to your bill. Compare that to what was actually withheld: if withholding was higher than the true cost, that gap effectively becomes part of your refund (or shrinks what you owe) at filing time — it isn’t lost, just held by the IRS in the meantime.
Flat Rate vs. Aggregate Method
The flat 22% rate isn’t the only option — some employers instead use the “aggregate method,” adding the bonus to your next regular paycheck and withholding as if that combined, larger amount were your normal pay for the period. Because payroll withholding tables assume that amount repeats every pay period, a big bonus stacked onto one paycheck often gets withheld at a noticeably higher effective rate than the flat 22% — sometimes over 30% for a large bonus on a modest salary. Either method reconciles to the exact same actual tax liability at filing time; only the amount withheld upfront (and therefore your refund or bill in April) differs.
Example: $10,000 Bonus, $80,000 Salary, Single
Withheld from the bonus: $2,200 (22% flat) + $620 Social Security + $145 Medicare = $2,965, leaving $7,035 net. But the bonus’s real cost: taxable income goes from $64,250 ($80,000 − $15,750 standard deduction) to $74,250 with the bonus — both fall inside the 22% federal bracket, so the true federal cost is $2,200, coincidentally matching the flat-rate withholding almost exactly here. Add the $765 in FICA (which isn’t refundable at filing time regardless), and this bonus is withheld almost precisely right — not every income level lines up this cleanly.
Frequently Asked Questions
Are bonuses actually taxed at a higher rate than regular pay?
No. At filing time, a bonus is just ordinary income added to everything else you earned, taxed at your normal marginal rate — there is no separate “bonus tax.” What feels like a higher rate is a withholding rule: employers can withhold a flat 22% from a bonus (37% above $1 million), regardless of your actual bracket.
Why did my bonus check seem to lose so much more than my regular paycheck?
The flat 22% federal withholding rate applies on top of the same FICA taxes as a regular paycheck. If your actual marginal tax rate is lower than 22%, you’re over-withheld on the bonus specifically — that extra amount comes back as part of your refund when you file, it isn’t lost.
What is the aggregate method, and is it different from the flat rate?
Some employers add the bonus to your regular paycheck and withhold as if that combined amount were your normal pay — often withholding MORE than the flat 22% method for a large bonus on a modest salary. Either way, your actual tax liability at filing time is the same — only the amount withheld upfront differs.
Does this include state income tax?
No — this calculator is federal-only. Many states have their own separate supplemental/bonus withholding rate that differs from their regular income tax brackets, which isn’t modeled here; add your state’s marginal rate separately for a fuller picture.
This calculator provides a simplified federal-only estimate using the flat 22%/37% supplemental withholding method. It does not model state income tax, the aggregate withholding method, or any pre-tax deductions taken from the bonus (401(k), etc.). Check a recent pay stub or a qualified tax professional for your specific situation.
