401(k) Withdrawal Tax Calculator: $20,000 at 45 Costs $5,860

Updated October 4, 2026. Quick answer: Cashing out pre-tax 401(k) money adds the withdrawal to your 2026 taxable income and taxes it in the brackets it fills, then adds a 10% additional tax if you are under 59 1/2 with no exception, and a cash-out of an eligible rollover distribution has 20% withheld. A single filer with $45,000 of other taxable income who withdraws $20,000 at 45 pays $3,860 (computed) of federal income tax ($5,400 at 12% and $14,600 at 22%, computed from Revenue Procedure 2025-32) plus $2,000 of additional tax, $5,860 in all (computed), and receives $16,000 after the $4,000 withheld, which leaves $1,860 owed at filing (computed). Enter your own numbers below.

State by state, the tax on your own withdrawals: state tax on 401(k) and IRA withdrawals, state by state.

Price an IRA withdrawal against the 2026 brackets: IRA withdrawal calculator.

Calculate the tax on your 401(k) withdrawal

This page prices a withdrawal. It does not tell you whether to take one or whether to roll the money over. Use it for a pre-tax (traditional) balance; the result runs on this page and sends nothing anywhere. Your other taxable income is the figure on your 2026 return after the standard or itemized deduction and before this withdrawal. The 2026 standard deductions are in the IRS release: “For tax year 2026, the standard deduction increases to $32,200 for married couples filing jointly. For single taxpayers and married individuals filing separately, the standard deduction rises to $16,100 for tax year 2026, and for heads of households, the standard deduction will be $24,150.”

The federal brackets are the 2026 tables in Revenue Procedure 2025-32. The withholding rate is yours to set: 20% is the mandatory rate on a cash-out, and your payer may use another rate if you give it a Form W-4R. State tax is a rate you enter, because states differ.

Early withdrawal tax and the 10% penalty, bracket by bracket

Three separate things happen to a pre-tax 401(k) cash-out. First, the amount is income: “You must include the taxable amount of a distribution that you don’t roll over in income in the year of the distribution.” Second, the section 72(t) additional tax: “the taxpayer’s tax under this chapter for the taxable year in which such amount is received shall be increased by an amount equal to 10 percent of the portion of such amount which is includible in gross income.” Third, the plan withholds: “the payor of such distribution shall withhold from such distribution an amount equal to 20 percent of such distribution.” The withholding is a prepayment, not the tax. The income tax is progressive, so the withdrawal is taxed in slices, starting where your other income ends.

1. Take your other 2026 taxable income and add the withdrawal.
2. Compute the 2026 tax on the larger figure and on your other income alone, from your filing status’s table.
3. The difference is the federal income tax on the withdrawal.
4. If you are under 59 1/2 with no exception, add 10% of the withdrawal.

Worked example, single filer, $45,000 of other taxable income, $20,000 withdrawn at age 45, no exception. The first $5,400 fills the 12% bracket (income up to $50,400): $5,400 x 12% = $648 (computed). The remaining $14,600 is taxed at 22%: $14,600 x 22% = $3,212 (computed). Federal income tax is $3,860, the 10% additional tax is $2,000 (10% x $20,000), and the total is $5,860 (computed).

2026 federal tax brackets used

The calculator reads these thresholds from the 2026 tax rate tables in Revenue Procedure 2025-32; the single and joint thresholds match the IRS news release IR-2025-103. The rate applies only to income above the threshold.

What a $20,000 withdrawal costs at different incomes

Single filer, age under 59 1/2, no exception, 20% withheld. The same withdrawal costs more as it lands in higher brackets.

Filing status moves the thresholds. Same $20,000 and $45,000 of other taxable income, by status:

When the 10% early withdrawal penalty does not apply

The additional tax is for early distributions. The statute lists the distributions it does not reach, including ones “made on or after the date on which the employee attains age 59½”, “attributable to the employee’s being disabled”, and “made to an employee after separation from service after attainment of age 55”. The IRS summary adds further exceptions for a 401(k): “Distributions made because you’re totally and permanently disabled.” “Distributions made to you because you are terminally ill.” “Distributions made to your beneficiary or estate on or after your death.” “Distributions up to $5,000 made to you from a defined contribution plan if the distribution is a qualified birth or adoption distribution.”

The calculator takes your word on which applies and removes the 10% when you pick one. The same single filer with $45,000 of other income and $20,000 withdrawn, by the age or exception picked:

The exceptions are narrower than they sound and each has its own conditions. They are set out on the early withdrawal penalty exceptions page and the age-55 rule on the 401(k) withdrawal rules page. A series of substantially equal payments is a way around the 10% that comes with its own rules, priced on the 72(t) calculator.

20% withholding is not the tax you owe

A taxable cash-out of a plan balance paid to you is usually an eligible rollover distribution, so the 20% is mandatory: “Any taxable eligible rollover distribution paid to you from an employer-sponsored retirement plan is subject to mandatory income tax withholding (generally at a rate of 20%), even if you intend to roll it over later.” The IRS also says the rate may fall short: “Note that the default rate of withholding may be too low for your tax situation.” In the worked example the 20% withheld is $4,000 against $5,860 of federal tax and additional tax, so $1,860 more is due when you file (computed). Some distributions are not eligible for rollover and so sit outside the mandatory rule. The IRS lists them: “A hardship distribution from an employer retirement plan;” Enter the rate your payer actually withholds in the calculator. The withholding rule is worked through on the 20 percent withholding page.

Three choices the tax number does not make

1. Cash out, roll over or leave it. A rollover is not a withdrawal for tax purposes: “If a plan pays you an eligible rollover distribution, you have 60 days from the date you receive it to roll it over to another eligible retirement plan.” The 20% is withheld even if you intend to roll over, so a 60-day rollover means finding the withheld amount from other money. Whether the money is better in the plan, an IRA or your pocket depends on fees, investments and creditor protection, not on this tax figure.

2. Which year and which income. The tax above depends on the other income in the same year. A withdrawal in a year with less other income fills lower brackets, and splitting a large withdrawal across two tax years can keep more of it out of the higher ones. The table above shows the cost per bracket; it does not choose the year for you.

3. How you take it. Taking only what you need, in a year the exception applies, or through a series of equal payments can remove the 10% additional tax but never the income tax. Several of these are on the retirement withdrawals guide hub and the loan alternative is on the 401(k) loan offset page.

Where this calculator stops

It prices a pre-tax withdrawal as ordinary income. It does not handle a Roth 401(k) balance or after-tax basis, net investment income tax, the interaction of the withdrawal with Social Security taxation, capital gains rates, credit and deduction phase-outs, the alternative minimum tax, employer stock, a plan loan offset or required minimum distributions. It does not compute state tax; it multiplies the rate you enter. The result is an estimate, and the IRS and your plan administrator decide the actual amounts.

Common mistakes

• Treating the 20% withholding as the tax. The tax is the bracket math plus any 10% additional tax; the 20% only prepays it.
• Entering your salary as other taxable income. Use taxable income after the standard or itemized deduction.
• Forgetting that the withdrawal stacks on top of your other income, so its first dollars are taxed at your top bracket, not your average rate.
• Rolling over only the amount you received. A 60-day rollover of the full balance needs the 20% that was withheld replaced from other money.
• Assuming an exception applies without checking its conditions, such as the age-55 exception, which requires that you have separated from service.

Related: 401(k) withdrawal rules, early withdrawal penalty exceptions, 20 percent withholding, the 72(t) calculator, and the RMD calculator.

Sources

• Internal Revenue Code section 72, 26 U.S.C. 72 (govinfo): https://www.govinfo.gov/link/uscode/26/72 (section page)
• Internal Revenue Code section 3405, 26 U.S.C. 3405 (govinfo): https://www.govinfo.gov/link/uscode/26/3405 (section page)
• IRS Topic no. 558, Additional tax on early distributions from retirement plans other than IRAs: https://www.irs.gov/taxtopics/tc558
• IRS Topic no. 413, Rollovers from retirement plans: https://www.irs.gov/taxtopics/tc413
• IRS news release IR-2025-103, tax year 2026 inflation adjustments: https://www.irs.gov/newsroom/irs-releases-tax-inflation-adjustments-for-tax-year-2026-including-amendments-from-the-one-big-beautiful-bill
• IRS Revenue Procedure 2025-32 (2026 inflation adjustments): https://www.irs.gov/pub/irs-drop/rp-25-32.pdf

Read from the Internal Revenue Code sections, the IRS pages and Revenue Procedure linked above on October 4, 2026. General information, not legal or tax advice. Your own facts decide the outcome, and your plan administrator, a tax professional or a benefits advisor is the right place to confirm anything consequential.