Tax Refund & Withholding (W-4) Estimator

• Starts from two numbers on your latest pay stub: federal tax withheld so far and per paycheck.
• Applies the 2026 child tax credit ($2,200 per child, up to $1,700 refundable) and the $500 credit for other dependents.
• Tells you the extra (or smaller) withholding per paycheck to break even, the number that goes in W-4 Step 4(c).
• Warns you when the balance due is large enough to risk an underpayment penalty.

How to use this calculator

Grab your most recent pay stub. Enter your expected wages for the whole year, the year-to-date federal income tax withheld, the federal tax taken from this paycheck, and how many paydays are left before December 31. Add your filing status and dependents. Open Advanced for other income, pretax 401(k) and health contributions, itemized deductions, other credits and estimated payments.

How the refund is estimated

The calculator works out your federal income tax for the year, subtracts your credits, and compares what's left with everything you will have paid in:

Tax = brackets applied to (wages + other income − pretax deductions − standard or itemized deduction)
Tax after credits = Tax − other credits − child/dependent credits (not below $0)
Payments = withheld so far + per-paycheck withholding × paychecks left + estimated payments
Refund (or amount owed) = Payments + refundable child credit − Tax after credits

The child tax credit is $2,200 per qualifying child under 17 for 2026 and the credit for other dependents is $500. Together they shrink by $50 for every $1,000 of income above $200,000 ($400,000 if married filing jointly). If the credit is larger than your tax, up to $1,700 per child can still be refunded, limited to 15% of earned income above $2,500.

A worked example

A single filer expects to earn $75,000 in 2026. By late September her stub shows $6,000 of federal tax withheld so far and $300 per paycheck, with 7 paychecks to go. Her taxable income is $75,000 − $16,100 standard deduction = $58,900, and the 2026 brackets put her tax at $7,670. She will have paid $6,000 + 7 × $300 = $8,100, so she is on track for a refund of about $430.

If she has one child under 17, the $2,200 credit cuts her tax to $5,470 and the projected refund grows to $2,630. At that point she could lower her withholding by roughly $376 per paycheck for the rest of the year and still break even, if she'd rather have the money now.

How to act on the result

If you'll owe: give your employer a new Form W-4 and enter the per-paycheck amount shown in Step 4(c), Extra withholding. If you'll get a large refund: you can reduce withholding the same way, or claim dependents in Step 3. Changes apply only to future paychecks, so the earlier in the year you check, the smaller the adjustment. Remember to revisit the W-4 in January so the extra amount doesn't carry into a year you don't need it.

Assumptions and limitations

• Federal income tax only. State tax, Social Security and Medicare are not part of the refund calculation.
• Other income is taxed at ordinary rates; qualified dividends and long-term gains may actually be taxed less.
• The Earned Income Tax Credit, education and energy credits and self-employment tax are not calculated. Enter known nonrefundable credits in Other credits.
• Assumes your per-paycheck withholding stays the same for the rest of the year and that the wage figure includes any bonus you expect.
• Uses 2026 figures from the IRS (Rev. Proc. 2025-32). It is an estimate for planning, not a tax return.

Common mistakes

Entering this paycheck's gross pay instead of the full year's wages. Forgetting a bonus (bonuses are often withheld at a flat 22%, which may be too little or too much). Counting a child who turns 17 during the year: the credit requires the child to be under 17 at the end of the year. And treating a big refund as a win: it means you lent the government money interest-free all year.

Frequently asked questions