Fill out your W-4 the easy way
Answer a few simple questions. We'll tell you exactly what to write on every line of your IRS W-4 form — in plain English, in under 2 minutes.
Start the W-4 Tool →What the W-4 actually does
Your IRS Form W-4 tells your employer how much federal income tax to withhold from every paycheck. Fill it out well and your withholding matches what you actually owe — meaning no surprise bill in April and no giant interest-free loan to the government.
Since 2020, the W-4 no longer uses allowance numbers (0, 1, 2...). Instead, it asks for dollar amounts: how much you earn from other jobs, how many dependents you have, and whether you want any extra withheld. The new form is more accurate — but the instructions are famously confusing. That is why this site exists.
Quick answers to common W-4 questions
Who needs to fill out a W-4?
You fill out a W-4 whenever you start a new job as an employee. You may also need to update it when your life or finances change. Common situations:
- Starting a new job — your employer is required to have a W-4 on file
- Getting married or divorced — changes your filing status and optimal withholding
- Having a baby or adopting — new dependents reduce your tax liability
- Taking on a second job or side hustle — additional income requires additional withholding
- Major income change — raise, demotion, or switching from salary to hourly
- Large tax bill or big refund last year — a signal your W-4 needs adjusting
Independent contractors do not fill out a W-4 — they fill out a W-9 instead. If you're unsure which applies to you, see our W-4 vs W-9 guide.