Bonus Tax Calculator
↻ Updated 2026 tax yearFind out your net bonus after tax. Uses the 2026 IRS supplemental-wage percentage method (22%, or 37% over $1M) plus FICA and state tax, and explains the aggregate method too.
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Runs entirely in your browser — nothing you enter is sent to us.How this works
How to read your net bonus
You keep 70.3% of the default $10,000 — $7,035 — and none of that is your tax bill. It's withholding: a flat 22% the IRS lets employers apply to supplemental wages, plus FICA. Your actual tax on the bonus is settled next April at whatever your real rate turns out to be.
How the 22% supplemental rate turns $10,000 into $7,035
Three withholdings, each computed on the gross bonus independently. Federal at the flat supplemental rate, FICA at the usual 7.65%, and state at whatever rate you set. Nothing is deducted first — there's no standard deduction on a bonus.
The federal piece is the one with a rule behind it. IRS Publication 15 lets an employer treat a bonus as a supplemental wage and withhold a flat 22%, no W-4 required. Above $1,000,000 in supplemental wages for the year the rate on the excess jumps to 37% — the top bracket, applied without brackets.
federal = 22% × bonus if bonus ≤ $1,000,000 = 22% × $1,000,000 + 37% × (bonus − $1,000,000) above it FICA = 6.2% × min(bonus, $184,500) ← Social Security + 1.45% × bonus ← Medicare + 0.9% × (bonus − threshold) ← if above state = bonus × state rate net = bonus − federal − FICA − state
- bonus
- The gross supplemental payment before anything is withheld — sign-on, annual, referral, retention — the IRS treats them alike as supplemental wages
- 22%
- The flat federal supplemental withholding rate — IRS Pub 15 percentage method — a withholding convention, not a tax rate anyone is assessed at
- 37%
- The rate on supplemental wages above $1,000,000 in a year — matches the top 2026 ordinary bracket; mandatory, not optional, for the employer
- $184,500
- The 2026 Social Security wage base — SSA 2026; this page tests it against the bonus alone, which is why the FICA line can overstate
- threshold
- Where the additional 0.9% Medicare tax starts — $200,000 single and head of household, $250,000 married filing jointly, $125,000 married filing separately
- state rate
- A flat rate you set — 0% in TX, FL, WA, NV, TN, SD, WY, AK, NH; many states set their own supplemental flat rate
The whole calculation is deliberately dumb, and that's the feature. A regular paycheck's withholding depends on your W-4, your filing status, your pay frequency and the standard deduction. The percentage method throws all of it away and takes 22% — which is why payroll departments like it and why the number on your bonus stub bears no particular relationship to what you owe.
FICA is the honest part: 7.65% on the bonus, same as on every other wage dollar, $765 on the default. It's also the part that doesn't come back. If your employer promised you a bonus 'net of tax', they're doing the arithmetic in reverse — the gross-up calculator runs it that way round.
Worked examples
Example: a $10,000 bonus, single filer, no state income tax
The calculator's defaults. A separate bonus check, withheld under the IRS percentage method.
| Gross bonuswhat was promised | $10,000 |
| Federal supplemental (22%)flat — your W-4 is irrelevant here | − $2,200 |
| Social Security (6.2%)assumes you're under the wage base | − $620 |
| Medicare (1.45%)no cap | − $145 |
| State income tax (0%)TX, FL, WA, NV, TN, SD, WY, AK, NH | − $0 |
| Total withheld29.65% of gross | $2,965 |
| Net bonus70.3% of gross | $7,035 |
$7,035 lands in your account — and that's the best case, in a state that takes nothing. Note the 29.65%: it's 22% + 7.65%, which is the number to remember, because it's the combined rate on almost every bonus under the wage base in a no-tax state. If your marginal federal rate is 12%, roughly $1,000 of that $2,200 comes back to you at filing.
Example: the same bonus with a 5% state rate
Move the state slider to 5% — roughly Illinois or Massachusetts territory. Nothing else changes.
| Gross bonusunchanged | $10,000 |
| Federal supplemental (22%)unchanged | − $2,200 |
| FICAunchanged | − $765 |
| State income tax (5%)the only line that moved | − $500 |
| Net bonusdown $500 | $6,535 |
| You keepdown from 70.3% | 65.3% |
Five points of state tax turned 70.3% into 65.3% — barely a third of the bonus now goes to withholding, and it's easy to see how people in high-tax states report bonuses 'taxed at 40%'. At California's top rate the arithmetic really does approach it. None of this changes what you owe; it changes when you pay it.
Frequently asked questions
Why is my bonus taxed at 40%?
Almost always because it wasn't taxed — it was withheld from, and by a method that ignores your circumstances. Two things produce a 40%-looking stub. Either your employer used the percentage method and you're adding up 22% federal, 7.65% FICA and a high state rate, which in California or New York genuinely lands near 40%. Or they used the aggregate method, which lumps the bonus onto a regular check and withholds as though you earned that much every pay period. Drop a $10,000 bonus onto the bi-weekly check of a $75,000 salary and payroll sees $12,885 for the period — which annualizes to about $335,000, and it withholds at the rate that income implies.
Either way it isn't your tax rate. Bonuses are ordinary income taxed at your ordinary brackets when you file. The difference between what was withheld and what you owe comes back as a refund.
How much of a $10,000 bonus do I actually keep?
$7,035 on this calculator's defaults — single, no state income tax. The withholding is $2,200 federal (22%), $620 Social Security and $145 Medicare, for $2,965 total, or 29.65% of gross.
Add state tax and it falls fast: 5% takes it to $6,535, and a 10% state rate leaves $6,035. But that's the withheld figure. What you finally keep depends on your marginal bracket. A single filer earning $75,000 sits in the 22% bracket, so the withholding is roughly right. Someone in the 12% bracket keeps about $1,000 more once they file.
Do you get bonus tax back on your refund?
You get back whatever was over-withheld — which for anyone below the 22% federal bracket is most of the federal piece. There's no separate bonus refund; the bonus is simply added to your wages on your return, taxed at your ordinary brackets, and the total withheld across the year is credited against the total owed.
FICA is the part that doesn't come back. The $765 on a $10,000 bonus is a real, final liability at 7.65% — no bracket, no refund. The one exception is Social Security overpayment: if two employers between them withheld on more than $184,500 of wages, you claim the excess as a credit on your return.
What's the difference between the aggregate and percentage method?
The percentage method — what this calculator uses — pays the bonus separately and withholds a flat 22% federal, regardless of your W-4. The aggregate method combines the bonus with a regular paycheck and withholds on the combined amount using your W-4 and the IRS wage-bracket tables, as though that inflated check were your normal pay.
The employer chooses, not you, and the choice is usually about payroll software rather than your interests. The percentage method is more predictable; the aggregate method is often more accurate for high earners and usually withholds more from everyone else, because it briefly treats one big check as a very large salary. Both true up at filing, so the difference is a cash-flow question, not a tax question. The take-home paycheck calculator shows what the aggregate method is extrapolating from.
Where this bonus calculator stops
It models one withholding method on one payment in isolation. Three of the gaps below can move the number on your actual stub.
- It withholds, it doesn't tax — Every figure here is what comes out of the check, not what you owe. Your bonus is ordinary income on your return and lands in whatever brackets your total year produces. The gap between the 22% withheld and your real marginal rate is the refund or the balance due.
- FICA is computed on the bonus alone — The Social Security cap and the additional-Medicare threshold are tested against the bonus, not against your wages plus the bonus. If your salary has already crossed $184,500, no Social Security is owed on the bonus and the real withholding is $620 lower than the default shows. If your salary is near $200,000, the 0.9% surtax may apply here when this page says it doesn't.
- The aggregate method isn't modelled — It's the other IRS-sanctioned option and the one behind most 'my bonus was taxed at 40%' stubs. Modelling it needs your regular wages, pay frequency and W-4 — none of which this page asks for.
- The $1M rate is real but out of reach here — The 37% rate on supplemental wages above $1,000,000 is in the formula and the slider stops at $100,000, so you can't demonstrate it on the page. It applies to cumulative supplemental wages for the year, not to a single payment.
- No 401(k), no state supplemental rates, no local tax — Many plans defer a percentage of bonuses into the 401(k), which would cut federal and state withholding and leave FICA untouched. States frequently set their own flat supplemental rate rather than using ordinary brackets, and local income taxes don't appear at all.
Rates, brackets and limits here are checked against primary sources. If a number still looks off, email support@realmoneyiq.com and we'll review and fix it.
RealMoneyIQ provides free educational calculators, not financial, tax, investment or legal advice. Results are estimates based on the assumptions you enter and publicly published rates; your actual outcome will differ. Always confirm decisions with a licensed professional who knows your full situation.