TL;DR
- ✅ Withholding is a prepayment of your income tax, taken from each paycheck
- ✅ Your W-4 plus the IRS tables decide the amount; FICA is separate and fixed
- ✅ A refund means too much was withheld; a bill means too little
- ✅ You can change it any time with a new W-4
What comes out of a paycheck
| Deduction | 2026 amount | Controlled by |
|---|---|---|
| Federal income tax | Varies by pay and W-4 | Your W-4 |
| Social Security | 6.2% of wages up to $184,500 | Law (fixed) |
| Medicare | 1.45% of all wages, plus 0.9% above $200,000 | Law (fixed) |
| State income tax | Varies by state; none in nine states | Your state form |
| Pre-tax benefits | 401(k), health insurance and similar | Your elections |
How your employer calculates federal withholding
Your employer turns your pay into an annual figure, applies your W-4 (filing status in Step 1, the multiple-jobs adjustment in Step 2, dependents in Step 3, and other income, deductions and extra withholding in Step 4), then looks up the tax in the IRS tables from Publication 15-T and divides it by the number of paychecks. This is why two people with the same salary can have very different amounts withheld. The form is covered line by line in the complete W-4 guide.
See how much is withheld from your pay — free
Enter your gross pay and filing status to see federal, Social Security, Medicare and take-home per paycheck.
Open the W-4 Calculator →Why withholding does not match your final tax
Withholding is a running estimate that assumes your paycheck is your only income all year. Your actual tax is figured on your return from your total income, deductions and credits. If more was withheld, you get a refund. If less, you pay the difference. The gap is usually caused by one of these:
- A second job or working spouse (see two jobs).
- Side income or interest with no tax withheld (see side income).
- A change in your life that your W-4 does not reflect (see when to update your W-4).
- A bonus withheld at the flat 22 percent supplemental rate.
⚠️ Withholding is not your tax bill
A big refund is not a bonus, and a bill is not a penalty. Both are the difference between what was withheld and what you owed. To target a refund or a zero balance, see how much to withhold and refund vs. adjusting your W-4.
Changing your withholding
You control the federal amount by submitting a new W-4 to your employer. State withholding uses your state’s form, and Social Security and Medicare cannot be changed. See your state’s withholding form, and how to stop owing taxes if you want to withhold more.
Frequently asked questions
What is federal withholding?
Federal withholding is the income tax your employer takes out of each paycheck and sends to the IRS on your behalf. It is a prepayment of your annual income tax, settled when you file your return.
How does my employer know how much to withhold?
From your W-4 and the IRS tables in Publication 15-T. Your filing status, dependents and any adjustments in Steps 2 to 4 are combined with your pay to produce a dollar amount for each paycheck.
What is the difference between withholding and FICA?
Federal income tax withholding depends on your W-4 and funds general government. FICA is Social Security (6.2% up to $184,500 in 2026) and Medicare (1.45% on all wages), and it is not affected by your W-4.
Why do I owe tax even though tax was withheld?
Withholding is an estimate. It can fall short if you have two jobs or a working spouse, side income, a bonus, or a W-4 that no longer fits your situation. You owe the gap when you file.
How are bonuses withheld?
Employers often withhold a flat 22 percent federal rate on bonuses paid separately from regular pay (37 percent on supplemental wages above $1 million in a year). Your real tax on the bonus is set when you file.
Key terms in this article
Related guides
How Much Federal Tax Should Be Withheld From Your Paycheck? (2026)
The IRS safe harbor, typical 2026 federal tax by income, and a 3-step check to see if you are withholding enough.
How to Fill Out a W-4 Form in 2026: Complete Step-by-Step Guide
Complete walkthrough of all five W-4 steps for 2026 — from filing status to extra withholding, the new OBBBA deductions, common mistakes and when to update.
W-4 Step 4 Explained: Other Income, Deductions, and Extra Withholding (2026)
Step 4 is how you fine-tune for side income, itemized deductions, and extra withholding. Most people skip it — here's when you shouldn't.
How Often Can You Change Your W-4? No Limit (2026 Guide)
No limit on how often, but timing matters: when your employer must apply it, and the changes you must report within 10 days.
Too Much or Too Little Tax Withheld? How to Tell and Fix Your W-4 (2026)
Signs, causes and W-4 fixes for withholding that is too high or too low, with a two-minute check.
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