PA Bonus Tax Calculator — Bonus & Supplemental Wage Withholding

Bonus & Supplemental Wage Tax Facts — 2026

Flat Rate vs. Aggregate Method

The IRS gives employers two ways to withhold federal tax on a bonus. The flat rate method — used by this calculator — applies a flat 22% to the bonus amount, separate from your regular paycheck. The aggregate method adds the bonus to your most recent regular paycheck and withholds based on the combined total using your W-4, which can result in a higher or lower withholding depending on your regular pay. Most employers use the flat method for standalone bonus checks, so it's the more common real-world scenario.

Neither method changes your actual tax liability — only how much is withheld upfront. Any difference gets reconciled when you file your return. Pennsylvania and local Earned Income Tax always apply at your normal flat rates, since PA does not have a separate supplemental wage rate the way the IRS does.

Curious how your bonus interacts with a specific city's local tax? Check Philadelphia, Pittsburgh, or Allentown, or browse every municipality on the PA Cities hub. For your regular paycheck, head back to the Tools hub or the main calculator on the homepage.

PA Bonus Calculator — FAQ

• How are bonuses taxed differently from regular wages? +
  At the federal level, employers can withhold tax on bonuses at a flat 22% rate instead of using your regular W-4 brackets — this is called the supplemental wage flat rate method. Pennsylvania, however, taxes bonuses exactly like regular wages: the same 3.07% flat state rate and the same local EIT rate apply, with no special bonus rate.
• Is 22% my actual tax rate on the bonus, or just withholding? +
  It's just withholding, not your final tax rate. The 22% flat rate is what your employer withholds upfront. Your actual federal tax liability on that income is determined when you file your return, based on your total annual income and bracket — you may get some of the withheld amount back as a refund, or owe more, depending on your overall tax situation.
• What happens if my bonus is over $1,000,000? +
  The IRS requires a higher 37% flat withholding rate on the portion of combined supplemental wages that exceeds $1,000,000 in a calendar year. The first $1,000,000 is still withheld at 22%; only the excess is withheld at 37%.
• Does my local EIT rate apply to bonuses? +
  Yes. Pennsylvania's local Earned Income Tax applies to bonuses at the same rate as your regular wages — there's no separate bonus rate at the state or local level, unlike the federal flat-rate treatment.
• Why might my actual paycheck bonus differ from this estimate? +
  Your employer may use the aggregate method instead of the flat rate method, which combines your bonus with a regular paycheck and withholds based on your W-4. Pre-tax deductions like 401(k) or health premiums taken from the bonus, or a Social Security wage base you've already hit, can also change the result. Your final tax liability is always settled when you file, regardless of which withholding method your employer used.