What this calculator does
Every paycheck, your employer holds back federal income tax and sends it to the IRS for you. How much is held back depends on the Form W-4 you gave your employer, not on the tax you will really owe. This calculator compares the two. It figures your likely 2026 federal income tax, adds up the tax already withheld and the tax that will still be withheld from your remaining paychecks, and shows whether you are heading for a refund or a bill. Then it suggests what to change on your W-4 so the year ends close to zero.
How employers figure withholding
Employers use the percentage method in IRS Publication 15-T (2026 edition). In plain steps, for a W-4 from 2020 or later:
- Annualize your pay. Your taxable pay for one paycheck is multiplied by the number of paychecks in the year (52, 26, 24 or 12).
- Adjust it with Step 4. Other income from Step 4(a) is added. Deductions from Step 4(b) are subtracted, along with a built-in amount that stands in for the standard deduction: $8,600, or $12,900 if you are married filing jointly. If you checked the Step 2(c) box, the built-in amount is zero and a different, higher-withholding table is used.
- Look up the tax. The adjusted amount is run through the IRS table for your filing status, then divided back into one paycheck.
- Subtract credits, add extra. The Step 3 credits are divided by the number of paychecks and subtracted. Any extra withholding from Step 4(c) is added on top.
The calculator follows these same steps with the 2026 tables, so the per-paycheck amount it shows should match payroll. If your pay stub shows a different amount, type it in and the calculator will use your stub for the rest of the year.
What each W-4 step means
- Step 2, multiple jobs. If you have two jobs, or you and your spouse both work, each employer withholds as if that job were your only income, which usually leaves you short. The checkbox is the simple fix when there are exactly two jobs with similar pay. For other cases, use the IRS estimator or the worksheet on the form.
- Step 3, credits. For 2026 you can claim $2,200 for each child under 17 who has a Social Security number and $500 for each other dependent. To claim the child credit, you (or your spouse, if you file jointly) must also have a Social Security number that is valid for employment; if not, count the children as other dependents. If your income is above $200,000 ($400,000 if married filing jointly), the credit shrinks, so enter less.
- Step 4(a), other income. Use it for income with no withholding, such as interest or side work, if you would rather pay through your paycheck.
- Step 4(b), deductions. Use it for deductions you expect besides the standard deduction: itemized deductions above the standard deduction, plus the new deductions for qualified tips, overtime, car loan interest and age 65+. The 2026 Form W-4 (2026) has a Deductions Worksheet that helps you total them, and the new tax deductions calculator shows how they work.
- Step 4(c), extra withholding. A flat dollar amount taken from every paycheck. It is the easiest way to fix a shortfall, and it can be changed or removed at any time.
How to use the result
Enter your pay, the paychecks you have received and the federal tax withheld so far (see your latest pay stub). Then enter what is true about your year and what your current W-4 says. If the calculator shows you will owe, it gives the extra amount to write in Step 4(c) for each remaining paycheck. If it shows a refund of $100 or more, it shows how much less could be withheld and which W-4 lines would do it. Only claim credits and deductions you really expect to have.
The earlier you change your W-4, the smaller the change per paycheck. A new W-4 only affects paychecks after your employer processes it, so late-year fixes need larger amounts.
What the estimate leaves out
This is a federal income tax estimate only. It does not include Social Security and Medicare tax, state or local tax, self-employment tax, the alternative minimum tax or the credits and adjustments many people claim on their return. It assumes every paycheck is the same all year, so bonuses, raises and unpaid leave will change the picture. For a result you can rely on, finish with the IRS Tax Withholding Estimator, which takes about 25 minutes and uses your actual pay stubs. It is not for nonresident aliens: their withholding follows different rules (IRS Notice 1392 and Publication 15-T).
This page is general information, not tax advice. Rates, tables and amounts are from IRS Publication 15-T and Revenue Procedure 2025-32 for 2026. They are listed in the sources below.
Frequently asked questions
Is it better to get a refund or owe a little?
Neither is "better" in itself. A refund means you lent the government money interest-free during the year. Owing a small amount means you kept more of each paycheck. The risk of owing a lot is an underpayment penalty, so many people aim to finish near zero.
Will I be charged a penalty if I owe at tax time?
Usually not if you owe less than $1,000 after withholding and credits. You can also avoid the penalty if your withholding and payments cover at least 90% of this year's tax or 100% of last year's tax (110% if last year's adjusted gross income was over $150,000). Form 2210 explains the rules.
How often should I check my W-4?
The IRS suggests checking your withholding every January and after a major change such as a new job, a raise, marriage, divorce, a new child or buying a home. You can give your employer a new W-4 at any time during the year.