There is no single right dollar figure for how much tax to withhold from your paycheck — the correct amount is whatever covers your projected federal tax bill for the year given your income, filing status, dependents, and deductions. You control it through Form W-4, and the fastest way to land on the right number is to run the IRS Tax Withholding Estimator, then transfer its recommendations onto a new W-4 for your employer.1Internal Revenue Service. Tax Withholding Estimator Aim for a small refund or a small balance due; a big refund means you loaned the government money for free, and a big balance due can trigger penalties.
What Actually Drives the Number
Federal income tax is graduated. You pay 10 percent on the first slice of taxable income and progressively higher rates — up to 37 percent in 2026 — only on the income that falls into each higher bracket. Before those rates apply, you subtract either the standard deduction or your itemized deductions. For 2026 the standard deduction is $16,100 for single filers, $32,200 for married filing jointly, and $24,150 for head of household.2Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026, Including Amendments From the One, Big, Beautiful Bill Taxpayers 65 and older can add $6,000 to that deduction through 2028, phasing out above $75,000 in modified adjusted gross income ($150,000 joint).3Internal Revenue Service. One, Big, Beautiful Bill Act: Tax Deductions for Working Americans and Seniors
Credits then reduce the tax itself, dollar for dollar. The 2026 Child Tax Credit is worth up to $2,200 per qualifying child under 17, plus $500 for other dependents; it starts phasing out above $200,000 in adjusted gross income ($400,000 joint).4Internal Revenue Service. Child Tax Credit More credits mean less tax owed, which means less needs to come out of each check.
Two other paycheck deductions are not variable and are not something the W-4 controls: Social Security tax at 6.2 percent on wages up to $184,500 in 2026, and Medicare tax at 1.45 percent on all wages, with an extra 0.9 percent on wages above $200,000 (or $250,000 joint).5Social Security Administration. Contribution and Benefit Base State income tax, where it applies, is set on a separate state form. Only the federal income tax line moves when you change your W-4.
Use the IRS Withholding Estimator First
The IRS Tax Withholding Estimator is a free online tool that does the math for you.1Internal Revenue Service. Tax Withholding Estimator You enter your expected wages, any bonuses, pre-tax retirement contributions, and year-to-date figures from your most recent pay stubs. It compares what has been withheld so far against your projected total tax for the year and tells you whether you are on pace for a refund, roughly even, or short.
From there it recommends exact entries for a new W-4 to hit whatever target you pick — a zero balance, a small refund, or a specific dollar amount.6Internal Revenue Service. IRS Tax Withholding Estimator Helps Taxpayers Get Their Federal Withholding Right Before starting, pull together your most recent pay stubs from every job you and your spouse hold, plus last year’s tax return. Those are the numbers the tool needs.
Filling Out Form W-4
Form W-4 is the Employee’s Withholding Certificate your employer uses to calculate the federal tax line on your paycheck.7Internal Revenue Service. About Form W-4, Employee’s Withholding Certificate You complete one when you start a job and can submit a new one at any time. It has five steps.
Step 1 is your name, address, Social Security number, and filing status. Step 2 is where you account for a second job or a working spouse; skipping this step when it applies is one of the most common causes of underwithholding, because each employer otherwise assumes yours is the only paycheck in the household. Step 3 is where you enter dependent credits: multiply qualifying children under 17 by $2,200, other dependents by $500, and put the total on the line.8Internal Revenue Service. Form W-4 (2026) Employee’s Withholding Certificate Step 4 is optional: non-wage income you want covered (dividends, interest, freelance earnings), itemized deductions above the standard amount, or a flat extra dollar amount you want withheld each pay period. Step 5 is your signature.
If the Withholding Estimator gave you specific numbers, this is where they go. Submit the completed form through your employer’s payroll portal or on paper. After the change takes effect, check the federal income tax line on your next pay stub and confirm the amount lines up with what the estimator projected.
Bonuses Are Withheld Differently
Bonuses, commissions, and other supplemental wages are not run through your W-4 the same way. Employers can withhold a flat 22 percent on supplemental wages up to $1 million in a calendar year, and 37 percent on any amount above that.9Internal Revenue Service. Publication 15 (2026), (Circular E), Employer’s Tax Guide That 22 percent is a withholding rate, not your actual tax rate. If your effective rate for the year is lower, the difference comes back as a refund; if it is higher, you may owe. Social Security and Medicare still come out of bonus pay at the usual rates.
Claiming Exempt From Withholding
If you had no federal income tax liability last year and expect none this year, you can claim exempt on Form W-4. Check the exemption box and skip the credit and deduction steps.8Internal Revenue Service. Form W-4 (2026) Employee’s Withholding Certificate Your employer will withhold zero federal income tax, though Social Security and Medicare still come out.
The exemption expires at the end of the calendar year. To keep it, submit a new W-4 claiming exempt by February 15. Miss that date and your employer must withhold as if you are single with no adjustments, which usually produces a noticeably larger deduction.10Internal Revenue Service. Topic No. 753, Form W-4, Employees Withholding Certificate Claiming exempt when you do not qualify can produce a large balance due and penalties at filing.
Stay Inside a Safe Harbor to Avoid Penalties
Withhold too little and the IRS can charge an underpayment penalty. You avoid it if any one of these applies:11Internal Revenue Service. Underpayment of Estimated Tax by Individuals Penalty
- Your balance due after withholding and credits is less than $1,000.
- Your total payments cover at least 90 percent of this year’s tax.
- Your total payments cover 100 percent of last year’s tax — or 110 percent if your prior-year adjusted gross income was above $150,000 ($75,000 if married filing separately).
Running the Withholding Estimator once a year is usually enough to stay inside one of those safe harbors. If you have significant income that is not subject to withholding — freelance work, rental income, investment gains — you may also need quarterly estimated tax payments on top of what your employer takes out.
When to Redo the Math
The right withholding amount at the start of the year can be the wrong amount by summer. Rerun the estimator and file a new W-4 when you:
- Marry or divorce, which changes your filing status.
- Have or adopt a child, adding a Child Tax Credit.
- Start a second job, or your spouse starts working. Combined income from two jobs is the classic underwithholding trap.
- Get a significant raise that pushes income into a new bracket.
- Begin earning non-wage income that has no withholding attached.
- Buy a home, since mortgage interest may make itemizing worthwhile.
The IRS recommends a check at the start of each year and again after any major financial change.8Internal Revenue Service. Form W-4 (2026) Employee’s Withholding Certificate Catching a shortfall in March gives you nine months of paychecks to spread the correction across. Catching it in November means one or two checks absorb the whole adjustment.