The W-4 tells your employer how much federal income tax to withhold from each paycheck. The current form has four main steps. Step 1 captures your filing status (Single, Married Filing Jointly, or Head of Household), which determines which tax brackets apply. Step 2asks whether your household has multiple jobs or a working spouse; checking this box triggers higher withholding so you don't end up short at tax time. Step 3 is where you claim dependent credits ($2,000 per child under 17, $500 per other dependent), which reduce withholding dollar-for-dollar.
Step 4 handles adjustments: line 4(a) for non-job income like interest or rental income, line 4(b) if your itemized deductions exceed the standard deduction, and line 4(c) for any additional per-paycheck withholding you want. Getting these right prevents a surprise bill or an oversized refund (which is essentially an interest-free loan to the government).
When should you update your W-4?
Figure out exactly what to put on your W-4 so you get the right amount withheld from each paycheck.
Include spouse's job(s) if filing jointly.
Only if married filing jointly and both work.
$2,000 credit each.
$500 credit each.
Interest, dividends, retirement income, etc.
Mortgage interest, state/local taxes, charitable contributions.
Optional additional amount to withhold each pay period.
This calculator provides estimates for informational purposes only. It uses simplified 2026 tax brackets and does not account for all credits, phase-outs, or special situations. Your actual withholding may differ based on your employer's payroll system. Consult a qualified tax professional for advice specific to your situation.
Want to make sure your W-4 is set up right?
Double-check your withholding with top-rated tax software, or have a professional review your setup.