W-4 Withholding Calculator
Check whether your 2026 paycheck withholding will cover your federal income tax, and how much extra to withhold on Form W-4.
About the W-4 Withholding Calculator
Compare your projected tax for the year (using 2026 brackets, the standard deduction and the child tax credit) with what's been withheld so far, then spread any shortfall over your remaining paychecks. Enter the extra amount in Step 4(c) of a new W-4. If you have several jobs or significant other income, use the IRS Tax Withholding Estimator for a precise result.
The formula
Extra per paycheck = (projected tax − withheld so far) ÷ paychecks left
Worked example
Example: Extra to withhold per paycheck = $314.44
- Inputs: Filing status: Single; Expected 2026 wages: $83,000; Other income (interest, side work): $0; Children under 17: 0; Federal tax withheld so far this year: $6,600; Paychecks left this year: 9.
- Formula: Extra per paycheck = (projected tax − withheld so far) ÷ paychecks left
- Result: Extra to withhold per paycheck = $314.44
Things to keep in mind
- Assumes withholding continues at the same rate on remaining paychecks only for the extra amount; FICA is separate.
Questions people ask
Will I owe a penalty?
Generally not if you owe under $1,000 or paid 90% of this year's tax (100%/110% of last year's).
When should I update my W-4?
After marriage, a new child, a second job or a big raise.
Sources
The rules and rates this calculator uses come from the official pages below. Its results are estimates, not an official determination, and rules change, so check the latest figures there before you act on them.