Skip to content
Calcapedia
Menu
Money

W-4 Withholding Calculator

Check whether the federal tax coming out of your pay will cover your 2026 tax, and how much extra to withhold per paycheck if it won't.

Level: Grade 7

  • Common Core standard 7.RP.A.3Use proportional relationships to solve multistep ratio and percent problems. Examples: simple interest, tax, markups and markdowns, gratuities and commissions, fees, percent increase and decrease, percent error.
Printable worksheet

W-4 Withholding Calculator

Inputs

The year-to-date federal taxable wages on your latest pay stub, after pre-tax 401(k) and health plan deductions.

Year-to-date federal income tax on your pay stub. Add any estimated tax payments you've made for 2026.

The federal taxable wages on one normal paycheck.

The federal income tax taken from one normal paycheck. Not Social Security or Medicare.

Count the paydays left in 2026. Paid every two weeks from late October, that's about 5 or 6.

Interest, side income or other taxable income for the year. This is W-4 Step 4(a).

Deduction

Deductions on top of the one above: tips, overtime and senior deductions, deductible IRA, student loan interest.

Each one is worth up to $2,200 off your tax, as in W-4 Step 3.

Up to $500 each, such as a child 17 or older.

Education, child care and similar credits you expect for 2026.

Result

Extra withholding per paycheck (W-4 Step 4(c))

$115.00

Your withholding looks about $688.00 short for 2026. Adding $115.00 to each of your 6 remaining paychecks (W-4 Step 4(c)) should cover it. Federal only; an estimate, not tax advice.

Where you stand
Close: about $688.00 owed
Projected amount owed with no change
$688.00
Projected 2026 federal income tax
$5,308.00
Projected withholding for the year
$4,620.00
Projected wages for the year
$62,400.00
Taxable income
$46,300.00

See the step-by-step solution ↓

Step-by-step solution

  1. Project your wages for the year: what you've earned so far, plus 6 more paychecks

    $48,000.00+$2,400.00×6=$62,400.00

  2. Project your withholding the same way: what's been taken out so far, plus the rest of the paychecks

    $3,600.00+$170.00×6=$4,620.00

  3. Add any other income, then subtract the 2026 standard deduction for single filers and any other deductions

    $62,400.00−$16,100.00=$46,300.00

  4. Work out the year's tax with the 2026 brackets. Each rate only applies to its own slice of income

    tax before credits=$5,308.00

  5. Compare the tax with what will be paid. The tax is bigger, so you're short

    $5,308.00−$4,620.00=$688.00

  6. Spread the shortfall over your 6 remaining paychecks

    $688.006=$114.67

  7. Round up to a whole dollar. Enter this in Step 4(c) of a new W-4

    extra per paycheck=$115.00

Test yourself

20 quick questions built from this calculator's formula: work out results, predict what happens when an input changes, and work backward from an answer. Every answer comes with the working.

Please note: Results are estimates for planning and comparison. Lenders, banks, and tax authorities may round differently or include fees not modeled here, so confirm figures with your provider before deciding.

What this calculator does

Find out if enough federal tax is coming out of your paychecks this year, and what to change if it isn't. Your employer withholds tax from every paycheck based on the W-4 form you filled out. That form is only a starting point. A raise, a second job, side income or a new child can leave you paying too little or too much.

Enter the numbers from your latest pay stub. The calculator projects your wages and withholding to the end of 2026 and estimates your tax for the year. If you're short, it divides the gap by your remaining paychecks. That's the extra amount to enter in Step 4(c) of a new W-4. It covers federal income tax only, not state tax, and it's an estimate, not tax advice.

Where it's used

Why this math matters outside the classroom:

  • Year-end projection. A worker with $48,000 earned so far and 6 checks of $2,400 left projects $62,400 of wages for the year.
  • Fixing a shortfall. Someone $688 short with 6 paychecks left divides to get $114.67 and asks for $115 extra on each one.
  • New baby. Parents with a newborn see their 2026 tax drop by $2,200 and can lower their withholding to match.
  • Side income. A worker with $46,300 of taxable income who tutors for $5,000 more owes $690 extra: 12% of $4,100 plus 22% of $900.
  • Budgeting class. Students multiply per-paycheck amounts by the paychecks left to compare projected tax paid with tax owed.

Grade level and standards: Grade 7; Common Core State Standards for Mathematics 7.RP.A.3. © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved.

How to use it

  1. Pick your filing status. Copy your year-to-date taxable wages and federal tax withheld from your latest pay stub.
  2. Enter the taxable wages and federal tax from one normal paycheck. Then count the paychecks left this year.
  3. Add any other income, deductions, children and credits you expect for the year.
  4. Read the extra amount per paycheck. If it's more than zero, enter it in Step 4(c) of a new W-4 and give it to your employer.

What the inputs mean

Taxable wages so far this year
Use the federal taxable wages on your pay stub, often labeled federal taxable or FIT wages. It's usually lower than your gross pay, because pre-tax 401(k) and health plan payments come out first.
Federal income tax withheld so far
Use the year-to-date federal income tax line, often labeled federal withholding or FIT. Don't include Social Security or Medicare. If you've made estimated tax payments for 2026, add them here too.
Taxable wages per paycheck
The federal taxable wages on one normal paycheck.
Federal income tax per paycheck
The federal income tax taken from one normal paycheck. Not Social Security or Medicare.
Paychecks left this year
Count the paydays still to come in 2026, not counting any that are already on your stub. Paid every two weeks from late October, that's usually 5 or 6. Paid twice a month, it's about 4.
Other income with no tax taken out (optional)
Income with no tax taken out, such as interest, freelance or rental income. This matches Step 4(a) on the W-4. Self-employment tax on freelance income isn't included here.
Expected itemized deductions
Mortgage interest, state and local taxes (up to the cap), charity and other Schedule A items.
Other deductions (optional)
Deductions on top of the standard or itemized amount. The 2026 deductions for tips, overtime premium and people 65 or older go here. So do deductible IRA contributions and student loan interest. The tax refund calculator can work out the tips, overtime and senior amounts.
Children under 17 (optional)
Each child under 17 at the end of 2026 with a Social Security number cuts your tax by up to $2,200. That's the same amount Step 3 of the 2026 W-4 uses. The credit shrinks above $200,000 of income ($400,000 joint).
Other dependents (optional)
Up to $500 each, such as a child 17 or older.
Other tax credits (optional)
Education, child care and similar credits you expect for 2026.

Formula and method

wages for the year = wages so far + wages per paycheck × paychecks left
withholding for the year = withheld so far + withholding per paycheck × paychecks left
tax = bracket tax on (wages + other income − deductions) − credits
shortfall = tax − withholding for the year − refundable child credit
extra per paycheck = shortfall ÷ paychecks left, rounded up to a whole dollar

Bracket tax means each slice of your taxable income is taxed at its own 2026 rate, from 10% to 37%. Credits come off the tax itself, dollar for dollar. Part of the child tax credit, up to $1,700 per child, is paid to you even if your tax is zero. So the calculator counts that part like money already paid.

If the shortfall is zero or less, you're on track, and the calculator shows your likely refund instead. If you're behind, spreading the gap over your remaining paychecks fixes it by year-end. The calculator rounds up, because Step 4(c) takes whole dollars and a few dollars over is safer than a few under.

This is a year-end projection, not your employer's payroll formula. Employers use the IRS tables in Publication 15-T, which can differ by a few dollars per paycheck. The goal here is to land close to zero owed in April.

Worked example

A single worker's pay stub shows $48,000 of taxable wages and $3,600 of federal tax withheld so far in 2026. Each paycheck has $2,400 of taxable wages and $170 of federal tax, and 6 paychecks are left.

  1. Wages for the year: $48,000 + $2,400 × 6 = $62,400.
  2. Withholding for the year: $3,600 + $170 × 6 = $4,620.
  3. Taxable income: $62,400 − $16,100 standard deduction = $46,300. Tax: $1,240 + 12% of $33,900 = $5,308.
  4. Shortfall: $5,308 − $4,620 = $688.
  5. Extra per paycheck: $688 ÷ 6 = $114.67, rounded up to $115.

Result: Adding $115 in Step 4(c) for the last 6 paychecks covers the shortfall. Without a change, this worker would owe about $688 when filing.

Understanding the result

On track means your withholding should cover your 2026 tax, with the extra coming back as a refund. If the refund is large, you could lower your withholding instead and keep more of each paycheck now.

Close means you'd owe less than $1,000. That's usually below the point where an underpayment penalty applies, but you'd still have a bill in April. Behind means you'd owe $1,000 or more, so adding withholding now is worth doing.

The Step 4(c) amount is for the rest of this year only. In January, fill out a new W-4 for 2027. Otherwise the extra keeps coming out of every paycheck all next year.

Assumptions and limitations

  • It uses the tax year 2026 brackets, standard deduction and child tax credit amounts published by the IRS.
  • Every remaining paycheck is assumed to look like the one you enter. Bonuses and raises still to come aren't included unless you build them into the per-paycheck numbers.
  • All income is ordinary income. Wages count as earned income for the refundable child credit, and your total income stands in for the modified AGI used by the credit's income limit.
  • This is an estimate, not tax advice. It doesn't reproduce the IRS Publication 15-T withholding tables your employer uses.
  • State income tax isn't included, and neither are Social Security and Medicare. Self-employment tax, capital gains rates and the alternative minimum tax are left out too.
  • For two jobs, or a married couple who both work, add up all the jobs' wages and withholding. Then put the whole extra amount on one W-4. The calculator doesn't split it between jobs.
  • It doesn't work out the tips, overtime or senior deductions itself. Enter them as other deductions.

Frequently asked questions

What is Step 4(c) on Form W-4?

Step 4(c) is where you ask your employer to take out extra federal income tax from every paycheck. You write in a dollar amount per pay period. It's the simplest way to fix a shortfall, because it doesn't change anything else on the form.

How do I know if my withholding is on track?

Compare the tax you'll owe for the year with the tax that will be withheld by December. Your pay stub has the withholding so far. This calculator adds the rest of the year and estimates your tax, so you can see the gap.

Is it better to get a refund or owe a little?

It's your choice. A refund means you lent the government money for free during the year. Owing a small amount means you kept more pay along the way. Owing $1,000 or more can bring a penalty, so many people aim for a small refund.

When should I update my W-4?

Check it at the start of each year and after big changes. These include a new job, a raise, marriage or divorce, a new child, or side income. Checking in the fall still leaves a few paychecks to make up a gap.

Sources

How this calculator is checked

Method: Year-end projection of wages and withholding; 2026 brackets and standard deduction from IRS Rev. Proc. 2025-32; child tax credit and credit for other dependents ($2,200 / $500) per the 2026 Form W-4 Step 3 and 2026 Schedule 8812 (draft); $1,000 balance-due threshold from the 2026 Form 1040-ES (figures in src/lib/finance/tax-2026.ts). Not the Publication 15-T percentage method. The calculation is covered by automated tests with known reference values and edge cases. Last updated 2026-10-25. Found a problem? Tell us.

Embed this calculator

Put this W-4 Withholding Calculator on your own website or blog for free. Paste this code where you want it to appear: