The Traditional vs Roth 401k comparison calculates whether paying taxes now (Roth) or deferring them to retirement (Traditional) saves you more money. The key variable is your tax rate now vs in retirement. Limits shown for 2026 — tax laws change annually, verify with IRS.gov.
Key Differences — 2026
| Feature | Traditional 401k | Roth 401k |
|---|---|---|
| Contributions | Pre-tax (reduces taxable income) | After-tax dollars |
| Tax on withdrawals | Taxed as ordinary income | 100% tax-free |
| 2026 limit (under 50) | $23,500 (combined) | $23,500 (combined) |
| 2026 limit (age 50+) | $31,000 catch-up | $31,000 catch-up |
| Income limits | None | None |
| Required Min Distributions | RMDs at age 73 | No RMDs (if rolled to Roth IRA) |
| Best for | Higher tax rate NOW than retirement | Same or higher rate in RETIREMENT |
Tax Savings Calculator
Traditional 401k
tax saved this year
Roth 401k
after-tax contribution
How to Compare Traditional vs Roth 401k
The Traditional vs Roth 401k decision comes down to one question: will your tax rate be higher now, or in retirement? Traditional wins if rates are higher now. Roth wins if retirement rates are the same or higher.
When Traditional 401k makes more sense
If you're in the 32-37% bracket today and expect to be in 22-24% in retirement, Traditional saves money. A $10,000 Traditional contribution at 32% saves $3,200 in taxes now. If you pay 22% on withdrawal, you net $1,000 ahead per $10K contributed.
When Roth 401k makes more sense
Young professionals early in their careers often pay lower rates today and will earn more later. A $10,000 Roth contribution at 12% costs $1,200 in taxes now. If that money grows to $80,000 tax-free, you saved all taxes on $70,000 of growth.
The Roth conversion ladder strategy
Many financial planners recommend contributing to Roth while in lower brackets, then switching to Traditional in peak earning years. The diversification of having both types gives you flexibility in retirement to manage your taxable income — pulling from Roth when income would otherwise push you into a higher bracket.
FAQ
Is this Traditional vs Roth 401k calculator free?
Yes, completely free with no signup required. Tax laws change annually — verify current contribution limits and income rules with the IRS.
What is the 2026 401k contribution limit?
For 2026, the 401k elective deferral limit is $23,500 per year ($31,000 for those age 50 or older with catch-up contributions). This limit applies combined to Roth and Traditional contributions. The total combined limit including employer contributions is $70,000.
Does Traditional or Roth win in most scenarios?
If your tax rate is higher now than it will be in retirement, Traditional wins (defer taxes to a lower rate). If your tax rate will be the same or higher in retirement, Roth wins (lock in today's rate and let it grow tax-free). Most people in peak earning years (high income) benefit from Traditional; younger workers and those expecting high retirement income often benefit more from Roth.
Can I have both Traditional and Roth 401k?
Yes, if your employer's plan offers both options, you can split contributions in any combination as long as the total stays under the $23,500 limit. This tax diversification approach gives you flexibility in retirement to withdraw from whichever account minimizes your tax bill that year.
What happens to employer match with Roth 401k?
Employer matching contributions always go into a Traditional pre-tax account, regardless of whether you contribute to Roth or Traditional. This means even if you choose Roth, your employer match will create a Traditional balance that will be taxable at withdrawal.
Who should choose Roth 401k?
Roth generally wins if you expect your retirement tax rate to be equal or higher than your current rate. This applies to: young people early in their careers (lower income now, higher later), those who expect significant retirement income, and those who want to hedge against future tax rate increases.