W-4 Withholding Calculator

The W-4 withholding estimator helps US employees calculate how much federal income tax their employer should withhold from each paycheck so they neither owe a large balance nor receive a windfall refund at tax time.

Estimated Annual Tax Formula:

Annual Tax = [Taxable Income − Standard Deduction] × Applicable Tax Rates (Brackets)

Where:

Taxable Income = Gross Income − Standard Deduction − Above-the-Line Deductions

2026 Standard Deductions: Single: $16,100 | MFJ: $32,200 | HOH: $24,150

2026 Federal Tax Brackets (Single):

• 10%: $0–$12,400
• 12%: $12,401–$50,400
• 22%: $50,401–$105,700
• 24%: $105,701–$201,775

Per-Paycheck Withholding:

Withholding Per Check = (Annual Tax − Tax Credits) / Pay Periods

Worked Example, single filer, $72,000 salary, 26 biweekly pay periods:

• Taxable income: $72,000 − $16,100 = $55,900
• Tax: (12,400 × 10%) + (38,000 × 12%) + (5,500 × 22%)
• = $1,240 + $4,560 + $1,210 = $7,010
• Less: Child Tax Credit (no children): $0
• Per paycheck withholding: $7,010 ÷ 26 = $269.62

Add two children under 17 and the Child Tax Credit takes $4,400 straight off the tax, leaving $2,610 for the year, or $100.38 a paycheck. That is the difference between a credit and a deduction: a credit comes off the tax itself, so it is worth the full amount whatever your bracket.

Getting it wrong in either direction costs you

Under-withhold and you owe at filing, plus a penalty if the shortfall passes the safe-harbour line. Over-withhold and you have handed the government an interest-free loan for up to sixteen months. A big refund feels like a win, but it is your own money coming back late.

The average refund runs well over $2,000, which is roughly $170 a month that could have been in your account all year. Most people would be better off dialling withholding down and putting the difference somewhere that pays interest.

Two jobs is where this breaks most often. Each employer withholds as though its salary is your only income, so both apply the lower brackets and the combined total lands short. W-4 Step 2 exists for exactly that case.

W-4 Step 3 lets you claim credits directly (e.g., $2,000 per qualifying child), reducing withholding dollar-for-dollar. Step 4(c) allows adding extra withholding per paycheck if you have side income. The IRS recommends updating your W-4 any time your life situation changes: marriage, new child, second job, or major income change.