If You Claim Single 0, How Much Tax Is Withheld?

If you claim Single with zero adjustments on your W-4, federal income tax withholding in 2026 runs roughly $187 per biweekly paycheck on a $50,000 salary, about $368 at $75,000, and about $579 at $100,000. Those are federal income tax only. Social Security and Medicare take another 7.65% of gross pay on top, and your W-4 has no effect on that piece. The exact figure depends on your salary, how often you’re paid, and whether you’ve written anything in Steps 2 through 4 of the form. Leaving those steps blank produces the highest default withholding available to a single-income filer.

What Single 0 Looks Like on Today’s W-4

The W-4 no longer uses allowances. The IRS eliminated them when it redesigned the form, so there is no “0” to enter anywhere.¹ To replicate the old Single 0 setting on the current form, you do three things: check “Single or Married Filing Separately” in Step 1, skip Steps 2, 3, and 4 entirely, and sign Step 5. That’s it.

The IRS confirms that when only Steps 1 and 5 are filled in, withholding is calculated using that filing status’s standard deduction and tax rates with no other adjustments.¹ New employees who never turn in a W-4 at all get exactly the same treatment by default.

Federal Income Tax Withheld at Common Salaries

Employers use the rate schedules in IRS Publication 15-T to compute withholding.² Your gross pay is annualized, run through the Single schedule, and divided back down to a per-paycheck amount. With a Single 0 setup there are no credits or adjustments modifying that calculation.

Assuming biweekly pay (26 checks a year) in 2026:

$50,000 salary: Annualized wages sit in the 12% bracket. Roughly $4,852 in federal income tax withheld per year, about $187 per paycheck.²
$75,000 salary: The top portion of the wage reaches the 22% bracket. About $9,562 per year, roughly $368 per paycheck.
$100,000 salary: Still in the 22% bracket but deeper into it. Around $15,062 per year, or about $579 per paycheck.

The 2026 Single schedule uses brackets starting at 0% on the first $7,500 of annualized wages and climbing through 10%, 12%, 22%, 24%, 32%, 35%, and 37% on wages above $648,100.²

Weekly, semi-monthly, or monthly pay changes the per-check dollar amount but not the annual total. Divide the annual figures above by your number of pay periods to estimate your own stub.

How the Math Works

Here is the calculation for a $75,000 salary paid biweekly with Single 0 settings, so you can check your own stub. Annual gross wages: $75,000. Because Steps 2, 3, and 4 are blank, no adjustments are subtracted, so the adjusted annual wage is $75,000.

On the 2026 Single schedule, $75,000 falls in the $57,900–$113,200 bracket. Base withholding at $57,900 is $5,800, plus 22% on every dollar above that threshold. The excess is $17,100. Twenty-two percent of $17,100 is $3,762. Add the $5,800 base and annual withholding is $9,562. Divided by 26 pay periods, that’s $367.77 per check.

Your stub may come out a few dollars different because some payroll systems use per-period tables instead of the annualize-and-divide method. Both come from Publication 15-T.

Why This Setting Withholds the Most by Default

Two things stack together. The Single filing status carries the smallest standard deduction: $16,100 in 2026, versus $32,200 for Married Filing Jointly and $24,150 for Head of Household.³ The Single withholding brackets are roughly half the width of the Married Filing Jointly brackets, so you hit higher rates on less income.

Blank Steps 2 through 4 then strip out every tax-reducing factor. Step 3 is where the Child Tax Credit ($2,200 per qualifying child in 2026) and the Credit for Other Dependents would go, both of which reduce tax dollar for dollar.⁴ Step 4(b) is where extra deductions above the standard amount would go. Leaving them empty tells payroll to assume none of it exists.

This is why Single 0 usually produces a refund at tax time. If you actually qualify for credits, itemize above the standard deduction, or file under a more favorable status, the money the IRS held onto through the year comes back.

Social Security and Medicare Come Out Separately

Federal income tax is not the only federal deduction. Social Security and Medicare (together called FICA) are withheld under a fixed statutory formula, and W-4 settings do not touch them. Every employee pays the same rate regardless of filing status.

For 2026, Social Security tax is 6.2% of gross wages up to $184,500.⁵ Once year-to-date earnings cross that ceiling, Social Security stops for the rest of the year. Medicare tax is 1.45% of all wages with no cap. Wages above $200,000 in a calendar year pick up an additional 0.9% Medicare surtax.⁶

On a $75,000 biweekly paycheck, FICA takes roughly $220, bringing total federal withholding to about $588 when combined with income tax. At $50,000, FICA runs about $147 per check.

When Single 0 Won’t Withhold Enough

The default setup assumes one job and no other income. If either assumption breaks, Single 0 quietly under-withholds, and the shortfall shows up as a tax bill in April.

A Second Job or a Working Spouse

If you hold two jobs, or file jointly with an earning spouse, each employer withholds as if its paycheck were your only income. Both give you the full zero-bracket space, effectively doubling a benefit you get only once. Step 2 of the W-4 fixes this with three options:¹

Step 2a: use the IRS Tax Withholding Estimator at irs.gov/W4app, which returns an extra dollar amount to write in Step 4(c) on one job’s W-4. Most accurate.
Step 2b: the Multiple Jobs Worksheet printed on page 3 of the form. Less precise but works on paper.
Step 2c: check a single box on both W-4s if there are exactly two jobs total and they pay similar amounts. Simple, but over-withholds when the two paychecks are very different.

Interest, Dividends, or Retirement Income

Step 4(a) is where non-wage income goes so the payroll formula can cover the tax on it. Enter the annual amount and the extra tax gets spread across your checks.⁴ Don’t put wages or self-employment income here. Ignoring meaningful non-wage income is one of the most common reasons people who thought they’d set up maximum withholding still end up owing.¹

If You Want Even More Held Back

Single 0 is the highest default, not the highest possible. Step 4(c) lets you name a flat extra dollar amount per paycheck. Write $100 there and payroll adds exactly $100 to whatever the formula already produced. That’s the only lever that pushes withholding above the Single 0 baseline.¹

Going the other way, Step 3 (dependents and credits) and Step 4(b) (deductions above the standard amount) reduce the estimated tax and lower each check’s withholding.⁴ The IRS Tax Withholding Estimator will produce a pre-filled W-4 based on your income, dependents, and expected deductions.⁷ Have your most recent pay stub and last year’s return handy.

After you hand in a revised W-4, your employer must put it in effect no later than the first payroll period ending on or after the 30th day from receipt.⁸ Plan for that lag if you’re changing mid-year.

1
Internal Revenue Service. FAQs on the 2020 Form W-4
2
Internal Revenue Service. Publication 15-T (2026), Federal Income Tax Withholding Methods
3
Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026, Including Amendments From the One, Big, Beautiful Bill
4
Internal Revenue Service. Form W-4 Employees Withholding Certificate 2026
5
Social Security Administration. Contribution and Benefit Base
6
Internal Revenue Service. Topic No. 751, Social Security and Medicare Withholding Rates
7
Internal Revenue Service. Tax Withholding Estimator
8
Internal Revenue Service. Form W-4, Employees Withholding Certificate