How to Fill Out a W-4 (and Set Your Withholding)
The W-4 tells your employer how much tax to hold back from each paycheck. Get it right and you avoid both a surprise bill and handing the IRS an interest-free loan.
Last updated: 2026-07-21
Every time you start a job you fill out a Form W-4. It does one job: it tells your employer how much federal income tax to withhold from each paycheck. The redesigned W-4 dropped the old allowances system, so instead of counting cryptic numbers you now answer plain questions about your situation.
The goal of withholding
Withholding is a running prepayment of your annual tax bill. Too little withheld and you owe money — possibly with a penalty — at tax time. Too much and you get a big refund, which feels nice but really means you lent the government your money interest-free all year. The sweet spot is withholding that lands you close to zero either way.
Working through the form
- Step 1 — your name, address, filing status.
- Step 2 — check the box if you have more than one job or a working spouse; this is the most common cause of under-withholding.
- Step 3 — claim dependents to reduce withholding if you qualify for the child or dependent credits.
- Step 4 — optional adjustments for other income, deductions, or an extra flat amount to withhold each pay period.
When to revisit it
You can submit a new W-4 any time, not just when you are hired. Update it after a marriage or divorce, a new baby, a second job, a big raise, or a year where you owed or were refunded a lot. A quick paycheck estimate before and after a change shows exactly how your take-home pay shifts.
See how your withholding choices change your take-home pay with the calculators below.