Total salary or wages before any deductions
From your pay stub (federal income tax line only)
Pre-tax retirement contribution
HSA, FSA, dental, etc.
Estimated Amount Owed
You may owe at tax time — consider increasing your withholding
Withholding vs Tax
$8,077$6,500$1,577W-4 Adjustment Recommendation
Increase your W-4 withholding by $61 per paycheck (Step 4c on Form W-4) to avoid owing at tax time.
FICA Breakdown
$5,270$1,233$6,503Full Breakdown
$85,000- $4,250- $3,900- $16,100$60,75022%9.5%$14,580Underpayment Penalty Risk
You may owe more than $1,000 at tax time. If your withholding was less than 90% of your total tax liability, the IRS may charge an underpayment penalty under IRC Section 6654. Consider increasing your W-4 withholding or making an estimated tax payment. Use the Estimated Tax Penalty Calculator to check.
OBBBA Changes Affecting 2026 Withholding
The One Big Beautiful Bill Act (OBBBA) has updated several provisions for 2026, including a higher SALT deduction cap ($40,400), a $400 minimum QBI deduction, and new deductions for car loan interest and tipped income. If these apply to you, your actual tax may be lower than estimated here, meaning your current withholding may result in a larger refund. Adjust your W-4 accordingly.
Disclaimer
This tool provides estimates for educational purposes only and is not tax advice. Results use 2026 federal figures and do not account for state taxes, credits, multiple jobs, or your full tax situation. Your actual withholding may vary based on employer methods and W-4 elections. Consult a qualified tax professional before making financial decisions.
How this is calculated
This calculator estimates whether your current federal income tax withholding is on track for 2026, following IRS Publication 15 and Publication 505:
- Annual pre-tax deductions = 401(k)% × gross income + pre-tax deductions per paycheck × pay periods.
- Taxable income = gross income − pre-tax deductions − 2026 standard deduction ($16,100 single, $32,200 MFJ, $24,150 HoH).
- Federal income tax = progressive brackets applied to taxable income using 2026 rates.
- FICA = 6.2% Social Security (up to $184,500) + 1.45% Medicare + 0.9% Additional Medicare above $200,000 (single) or $250,000 (MFJ).
- Annual withholding = federal tax withheld per paycheck × pay periods.
- Withholding gap = annual withholding − federal income tax. Positive = refund; negative = amount owed.
- Per-paycheck adjustment = withholding gap ÷ pay periods, to bring you to break-even.
Worked example: Single filer with $85,000 gross income, 5% 401(k) contribution ($4,250), $150/paycheck pre-tax deductions (biweekly = $3,900/year), $250 federal withholding per biweekly paycheck. Taxable income = $85,000 − $4,250 − $3,900 − $16,100 = $60,750. Federal income tax on $60,750 (single 2026 brackets): $1,192.50 (10%) + $4,386 (12%) + $3,619 (22%) = ~$9,198. Annual withholding = $250 × 26 = $6,500. Withholding gap = $6,500 − $9,198 = −$2,698 (you owe). Adjustment: increase W-4 Step 4c by $2,698 ÷ 26 ≈ $104 per paycheck to break even. FICA: Social Security = $85,000 × 6.2% = $5,270, Medicare = $85,000 × 1.45% = $1,233, Total FICA = $6,503.
Sources
- IRS Publication 15 — Employer's Tax Guide
- IRS Publication 505 — Tax Withholding and Estimated Tax
- IRS Form W-4 — Employee's Withholding Certificate
Reviewed against 2026 figures · Last updated June 11, 2026 · Written by Zhisuan
Data sources & legal references
- IRC §1 — Federal income tax rates and brackets
- IRC §63(c) — Standard deduction amounts for 2026
- IRC §3101 — FICA tax rates (6.2% SS + 1.45% Medicare)
- IRC §3101(b) — Additional Medicare Tax (0.9% above threshold)
- IRC §6654 — Underpayment of estimated tax penalty
- IRS Publication 15 (2026) — Employer's Tax Guide
- IRS Publication 505 (2026) — Tax Withholding and Estimated Tax
- IRS Form W-4 — Employee's Withholding Certificate
- IRS Revenue Procedure 2025-32 — 2026 inflation-adjusted items
- 2026 SS wage base: $184,500 | Additional Medicare thresholds: $200,000 (single), $250,000 (MFJ)
Tax law references are based on the Internal Revenue Code and IRS publications. For questions about this content, contact the author.
What is How to Use the Tax Withholding Calculator?
Federal tax withholding is the amount your employer deducts from each paycheck to cover your estimated federal income tax liability for the year. Getting withholding right matters: too little and you face a surprise tax bill plus potential underpayment penalties under IRC §6654; too much and you give the government an interest-free loan instead of earning returns on that money yourself. The 2020 redesign of Form W-4 eliminated allowances and replaced them with a five-step process that accounts for multiple jobs, dependent credits, and other adjustments. This calculator estimates whether your current withholding is on track for 2026 by comparing your projected annual withholding against your estimated federal income tax liability. It factors in your 401(k) contributions, pre-tax deductions (HSA, FSA, health insurance), the 2026 standard deduction, and the full progressive bracket structure. It also breaks down your FICA taxes — 6.2% Social Security up to the $184,500 wage base, 1.45% Medicare on all wages, and 0.9% Additional Medicare Tax above $200,000 (single) or $250,000 (MFJ). The calculator provides a specific per-paycheck W-4 adjustment recommendation: how much to add or subtract on Step 4c to bring your withholding closer to break-even. It also flags underpayment penalty risk if you are projected to owe more than $1,000 at tax time.
How to Use
- Enter your annual gross income
- Select your filing status and pay frequency
- Enter the federal tax withheld on your most recent paycheck
- Add any 401(k) contributions and pre-tax deductions
- See whether you are on track for a refund or balance due
Why Use This Tool?
Tips & Best Practices
- A large refund is not free money — it means you overpaid throughout the year and missed out on investment returns
- Submit a new W-4 to your employer to adjust withholding; changes take effect on your next paycheck
- If you owe more than $1,000 and your withholding was less than 90% of your tax, you may face an underpayment penalty
- The 2026 standard deduction is $16,100 for single filers and $32,200 for married filing jointly
- Multiple jobs or a working spouse? Check the W-4 Step 2 box or use the IRS Tax Withholding Estimator for more accuracy
Frequently Asked Questions
How do I know if my withholding is correct?
Your withholding is correct if you neither owe a large balance nor receive a large refund at tax time. Aim for a refund or balance due under $500. A large refund means you over-withheld and gave the government an interest-free loan.
How do I adjust my W-4 withholding?
Submit a new Form W-4 to your employer. On the 2020+ W-4, use Step 4c to add extra withholding per paycheck, or Step 3 to claim dependent credits. Changes take effect on your next paycheck.
What happens if I under-withhold?
If you owe more than $1,000 at tax time and your withholding was less than 90% of your tax liability, you may owe an underpayment penalty (IRC Section 6654). The penalty is essentially interest on the underpaid amount.
What is the 2026 standard deduction?
The 2026 standard deduction is $16,100 for single filers, $32,200 for married filing jointly, and $24,150 for head of household.
Should I aim for a refund or break even?
Financially, breaking even is optimal — you keep more money in each paycheck to invest or save. A large refund means you overpaid throughout the year. However, some people prefer over-withholding as forced savings.
What does this calculator NOT cover?
This calculator does not model state income tax withholding, tax credits (child tax credit, earned income credit, education credits, Saver's Credit), the QBI deduction, itemized deductions, capital gains tax rates, self-employment tax, the alternative minimum tax (AMT), the OBBBA car loan interest deduction, tipped income deduction, or multiple jobs/spouse income. It uses the standard deduction only and does not account for additional standard deduction amounts for age 65+ or blindness. FICA calculations assume all income is from wages (not self-employment). Consult a tax professional for your complete tax situation.
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