Roth vs Traditional · Tax Split

Roth vs Traditional 401(k) Calculator: which leaves you more?

Both options start from the same slice of gross salary. The Roth column pays tax up front and invests less; the traditional column invests the full amount and settles with the IRS on withdrawal. Enter your tax rate today and in retirement to see which one ends with more spendable money.

No sign-up, nothing stored. The verdict updates as you change any rate.

Roth vs Traditional 401(k) Calculator

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Pre-tax deferral

Traditional 401k

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After-tax deferral

Roth 401k

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Both columns start from the same slice of gross salary. The Roth column loses the tax up front, so less money is actually invested; the traditional column invests the full amount and settles with the IRS at distribution. If your rate falls in retirement, traditional wins; if it rises, Roth wins.

Same gross contribution · tax now vs tax later — every figure recalculates as you type

Should You Choose a Roth or Traditional 401(k)?

The decision comes down to one comparison: your marginal tax rate today against your expected rate when you withdraw. A traditional 401(k) invests the full pre-tax amount and taxes it on the way out; a Roth 401(k) taxes it now and lets every dollar, growth included, come out tax-free. With identical rates the two land on exactly the same spendable amount — the calculator above shows how far apart they drift when the rates differ.

Traditional 401(k)Roth 401(k)
Tax on contributionsDeducted from taxable payPaid now
Tax on withdrawalsOrdinary incomeNone if qualified (59½ and 5 years)
2026 contribution limit$24,500 combined across both, plus catch-ups
Required minimum distributionsFrom age 73None during your lifetime
Employer matchPre-taxPre-tax by default; Roth only if the plan allows and you pay the tax

When Does Roth Win and When Does Traditional Win?

Roth tends to winEarly-career, lower bracket today, expected higher income or higher tax rates later
Traditional tends to winPeak earning years, high bracket now, planned move to a lower-tax state in retirement
Close to a tieSimilar rates now and later — split contributions for tax diversification
Hidden Roth bonusNo RMDs, and tax-free income does not raise the taxable share of Social Security
New for 2026: Roth catch-ups for high earners

If your prior-year FICA wages from the employer exceeded $150,000, any catch-up contributions you make at 50+ must now go in as Roth. Your base $24,500 can still be traditional.

How Should You Fill In the Calculator?

  1. Annual contributionEnter the gross amount you would defer — the same slice of salary under either option.
  2. Marginal tax rate todayYour top federal bracket plus state income tax, not your average rate.
  3. Expected rate in retirementEstimate from your planned withdrawals, Social Security and pensions; many retirees fall one bracket lower.
  4. Return and yearsUse a conservative long-run return after fees; the gap widens the longer the money compounds.

To see how the chosen contribution builds over a full career with your employer match, open the 401(k) growth calculator. For the popular “Roth first” rule of thumb, read the Dave Ramsey Roth 401k recommendation.

Roth vs Traditional Questions

Can I contribute to both a Roth and a traditional 401(k)?

Yes, if your plan offers both. The $24,500 limit applies to the total, so you can split it in any proportion.

Can I convert my traditional 401(k) to Roth?

Many plans allow in-plan Roth conversions, and you can convert after rolling into an IRA. The converted amount is taxable income in the year of conversion.

Does a Roth 401(k) have income limits?

No. Unlike a Roth IRA, a Roth 401(k) is open to every participant regardless of income.

What is the five-year rule?

Earnings come out tax-free only once you are 59½ and at least five tax years have passed since your first Roth 401(k) contribution to that plan.

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