Bonus Tax Calculator Guide: How Much of Your 2026 Bonus Do You Actually Keep?
Getting a bonus is exciting — until you see how much disappears before it hits your bank account. This guide explains exactly how bonus withholding works in the US, which method your employer is likely using, and the legal strategies you can use to keep more of your money.
Flat supplemental withholding rate: 22% (up to $1,000,000) / 37% (above $1,000,000)
Social Security wage base: $176,100 (6.2% employee share up to this cap)
Additional Medicare Tax threshold: $200,000 single / $250,000 married filing jointly (+0.9%)
Standard Medicare rate: 1.45% on all wages (no cap)
How Bonus Withholding Actually Works
Bonuses are classified by the IRS as supplemental wages — any compensation paid in addition to your regular salary. This classification gives employers two methods for withholding federal income tax, and the choice between them can meaningfully change how much appears in your check.
It is critical to understand that withholding is not the same as your final tax. Regardless of which method your employer uses, you reconcile everything on your annual tax return. If too much was withheld, you get a refund. If too little, you owe. The method only affects your cash flow during the year.
Method 1 — Flat Rate (Most Common for Separate Bonus Checks)
When an employer pays a bonus as a separate check — not combined with your regular paycheck — the flat method is the most common approach. The employer simply withholds a flat 22% for federal income tax on the first $1,000,000 of supplemental wages you receive in a calendar year. Any supplemental wages above $1,000,000 are withheld at 37%.
Federal (22%): $1,760
State (e.g. NY 10.9%): $872
Social Security (6.2%, under $176,100 cap): $496
Medicare (1.45%): $116
Total withheld: $3,244 → Net take-home: $4,756 (effective rate: 40.6%)
Method 2 — Aggregate Method (Bonus Added to Regular Pay)
Some employers add the bonus to your regular pay for that period and withhold based on your W-4 rate as if you earned that combined amount every pay period. This can sometimes withhold more than the flat method — particularly if the combined check pushes you into a higher withholding bracket — or occasionally less if your normal withholding rate is below 22%.
Combined biweekly gross: $11,250
Annualised for withholding: $292,500 → 35% bracket withholding
Federal withheld on bonus portion: ~$1,750 (35%)
vs Flat method: $1,100 (22%)
Aggregate withholds ~$650 more in this scenario
FICA Taxes on Bonuses (Social Security & Medicare)
In addition to income tax withholding, bonuses are subject to payroll (FICA) taxes. These are separate from federal income withholding and are calculated independently:
| Tax | Rate | 2026 Cap / Threshold | Notes |
|---|---|---|---|
| Social Security | 6.2% | $176,100 wage base | Stops at cap — major relief for high earners |
| Medicare | 1.45% | No cap | Applies to every dollar |
| Additional Medicare | +0.9% | $200k single / $250k MFJ | Employee only (no employer match) |
If you have already exceeded the $176,100 Social Security wage base before your bonus is paid, you owe zero Social Security on the bonus — a meaningful saving of up to $10,918. Enter your YTD wages in the calculator to get an accurate estimate.
State Tax on Bonuses — How Much Varies by State
Many states use a flat supplemental wage withholding rate for bonus income, which can differ from their standard income tax rates. Nine states have no income tax at all, while California tops the list at 10.23% for supplemental wages (with the top marginal rate at 13.3%). New York City residents face state plus city tax totalling over 14% on bonuses.
| State | Supplemental Rate | Notes |
|---|---|---|
| California | 10.23% | Among highest in US |
| New York | 10.9% | NYC adds up to 3.876% extra |
| Oregon | 9.9% | |
| Minnesota | 9.85% | |
| New Jersey | 5% (flat) | Lower than income bracket |
| Texas, Florida, Nevada, WA | 0% | No state income tax |
| Illinois | 4.95% (flat) | Flat for all income levels |
| Pennsylvania | 3.07% (flat) | One of the lowest |
Legal Strategies to Reduce Bonus Withholding
1. Maximise pre-tax deductions. Any contributions to a traditional 401(k), 403(b), HSA, or FSA from your bonus reduce the taxable amount before withholding is calculated. For example, routing $2,000 of a $10,000 bonus into your 401(k) reduces your federal withholding base to $8,000 — saving $440 in flat-rate withholding alone.
2. Check your Social Security cap status. If you earn over $176,100 in regular wages before your bonus is paid, your bonus is not subject to the 6.2% Social Security tax. At a $20,000 bonus this saves $1,240.
3. Adjust your W-4. If you consistently get large refunds due to bonus over-withholding, you can adjust your W-4 to reduce withholding on your regular pay. This is legal and simply shifts cash flow — your total annual tax stays the same.
4. Timing.** If you have significant control over when a bonus is paid, receiving it in a year when your total income is lower (e.g. early retirement, career transition) can reduce your actual tax owed — though withholding is the same regardless.
Related Calculators
- Take-Home Pay Calculator — estimate net pay from any gross salary
- Overtime Pay Calculator — calculate time-and-a-half and double time
- Pension Calculator — plan how to invest your net bonus in your retirement pot
- Capital Gains Tax Calculator — if you invest your bonus, estimate the tax on gains
- Percentage Calculator — quick percent and rate calculations