What is FITW (2026) | PaycheckByState

What is FITW? FITW is federal income tax withholding: the amount your employer takes from each paycheck and sends to the IRS as an advance payment of your income tax. It is calculated from your Form W-4 and IRS Publication 15-T, and it is only an estimate — your actual tax is settled when you file.

What does FITW mean on my paycheck?

FITW stands for federal income tax withholding. It is the part of each paycheck your employer sends to the IRS as a prepayment of the income tax you will owe for the year. It is separate from FICA (Social Security and Medicare), which you can decode in our pay stub abbreviations guide.

Payroll systems label it many ways: FITW, FIT, FED W/H, FEDERAL TAX, FWT. They all mean the same thing. It is usually the largest deduction on a stub after taking home pay into account, and the only major one you can change directly by filing a new W-4.

How FITW is calculated

Employers use the percentage method in IRS Publication 15-T. In plain steps:

Take your gross pay for the period and annualize it (multiply by 26 for biweekly, 24 for semi-monthly, 12 for monthly, 52 for weekly).
Subtract pre-tax deductions such as 401(k) and health premiums, and add or subtract the adjustments from your W-4 Step 4.
Subtract the standard deduction built into the tables ($16,100 single, $32,200 married filing jointly for 2026, before W-4 adjustments).
Apply the 2026 tax brackets to the result. See the 2026 federal tax brackets.
Subtract credits claimed on Step 3, divide by the number of pay periods, and add any extra withholding from Step 4(c).

The result is withheld from that paycheck. Nothing about your state, your total year-to-date income or your real refund enters the calculation, which is why withholding is only an estimate.

FITW at common salaries (2026)

Federal income tax withheld per year and per biweekly paycheck, with no pre-tax deductions, no W-4 adjustments and standard withholding. Figures come from this site's calculator, which follows Publication 15-T.

Annual pay	Single: FITW / year	Single: per paycheck	Married: FITW / year	Married: per paycheck
$30,000	$1,420	$55	$0	$0
$45,000	$3,220	$124	$1,280	$49
$60,000	$5,020	$193	$2,840	$109
$80,000	$8,770	$337	$5,240	$202
$100,000	$13,170	$507	$7,640	$294
$150,000	$24,734	$951	$15,340	$590

Run your own numbers, including 401(k) and dependents, in the free paycheck calculator.

What on your W-4 changes FITW

Step 1(c) filing status: single, married filing jointly or head of household. Married filing jointly gets a larger built-in deduction and wider brackets.
Step 2 multiple jobs: checking the box (or using the estimator) makes each job withhold as if it were your only income at a higher bracket, preventing under-withholding.
Step 3 credits: child and other dependent credits reduce withholding dollar for dollar.
Step 4(a)–(c): other income, extra deductions, and extra flat withholding per pay period.

See the full walkthrough in the Form W-4 guide.

Why your FITW changed

A raise or overtime: more annualized income can move part of your pay into a higher bracket. See overtime and taxes.
A bonus: usually withheld at a flat 22%. See bonus tax.
Changing pre-tax benefits: more 401(k) or HSA lowers taxable pay and FITW. See pre-tax deductions.
A new W-4: takes effect within a few pay periods.
New tax year: tables and standard deductions are updated each January.

How to raise or lower your FITW

Complete a new W-4 and give it to your employer or payroll portal. To withhold more (avoid a bill), enter an extra amount on Step 4(c). To withhold less, claim credits on Step 3 or deductions on Step 4(b) that you are truly entitled to. Use the IRS Tax Withholding Estimator for a reliable answer, then check the effect on take-home pay with the paycheck calculator. You may claim exempt only if you had no federal tax liability last year and expect none this year.

FITW is not your final tax

At filing time your actual tax is calculated from your whole year: all income, deductions and credits. Total FITW is subtracted from it. If more was withheld, you get a refund; if less, you owe. A large refund simply means you lent the government money interest-free during the year. This is general information, not tax advice. For the bigger picture of what employers withhold and why, read what withholding tax is.

Frequently asked questions

What is FITW on my paycheck?

FITW is federal income tax withholding: the amount your employer takes from each paycheck and sends to the IRS as an advance payment of your income tax. It is not the same as Social Security or Medicare.

Is FITW the same as FIT?

Yes. FITW, FIT, FED W/H and FEDERAL TAX are different labels for the same line: federal income tax withheld.

Is FITW the tax I actually owe?

No. It is an estimate based on your W-4. When you file, your real tax is compared with the total withheld, and you receive a refund or owe the difference.

Why is my FITW higher on a bonus?

Bonuses paid separately are usually withheld at a flat 22% (37% above $1 million in a year). See the bonus tax guide. The final tax is settled at filing.

How do I change my FITW?

Give your employer a new Form W-4. Use Step 3 for credits, Step 4(a) for other income, 4(b) for deductions and 4(c) for extra withholding per paycheck. The IRS Tax Withholding Estimator helps you pick the numbers.