Free Accounting Tool
W-4 Calculator
Estimate the right federal tax withholding for your paycheck and what to put on Form W-4 lines 4a, 4b, and 4c.
Remaining checks in the tax year after your latest paystub
Each qualifies for a $2,200 Child Tax Credit
Each qualifies for $500 credit
Interest, dividends, side gigs not on a W-2
Itemized amount above the standard deduction
From your most recent paystub
Used to estimate Form W-4 line 4c
Withholding plan
Required withholding per remaining paycheck
$295.00
- Estimated annual federal tax
- $7,670.00
- Tax credits applied
- $0.00
- Average per paycheck for full year
- $295.00
- Remaining tax after YTD withholding
- $7,670.00
- Projected amount due
- $7,670.00
- Suggested extra per paycheck (W-4 line 4c)
- $295.00
Estimate only. Federal income tax only. Does not model state tax, FICA, pre-tax payroll deductions, credit phaseouts, the multiple-jobs worksheet, two-earner households, or new OBBB deductions for qualified tips and overtime.
Frequently asked questions
What does the W-4 form actually do?
It tells your employer how much federal tax to withhold from each paycheck. The form does not file your taxes; it estimates throughout the year what you will owe so you do not face a big bill (or a big refund) at filing time.
When should I update my W-4?
Anytime your situation changes: a new job, marriage, divorce, a child, a second job, a big bonus, or a side business. Also when you get a surprise refund or balance due, that means your withholding is off.
What is the difference between lines 4a, 4b, and 4c?
Line 4a is "Other income" not from jobs (interest, dividends, side gigs). Line 4b is "Deductions" above the standard deduction. Line 4c is "Extra withholding" — a flat extra dollar amount per paycheck. This calculator suggests a 4c amount when you are under-withheld.
How does the Child Tax Credit factor in?
Each qualifying child under 17 reduces your federal tax by up to $2,200 for 2026. Other dependents qualify for a $500 credit. On Form W-4, you enter the total credit amount on line 3.
Why does my employer say I am withholding too little?
Most often because of a second job, a working spouse without the box checked, or other taxable income. The IRS Tax Withholding Estimator and the Multiple Jobs Worksheet on the W-4 are designed to handle these. Adding a flat 4c amount is the simplest fix.
Is this calculator a substitute for the IRS Tax Withholding Estimator?
No. This is a quick planning tool. For the most accurate result, use the IRS Tax Withholding Estimator at irs.gov, especially if you have multiple jobs, a working spouse, large bonuses, or significant non-wage income.
Sources
- IRS Publication 15-T (2026)
Federal income tax withholding methods and Form W-4 guidance for employers.
- IRS Tax Withholding Estimator
Official IRS withholding estimator for more complex household situations.
- IRS Rev. Proc. 2025-32
2026 federal brackets, standard deductions, and Child Tax Credit amounts.