Roth 401k vs Traditional 401k 2026 Comparison Calculator
See which account wins for your situation — enter your contribution, current tax bracket, expected retirement bracket, growth rate, and years to compare net after-tax retirement balances side-by-side using the 2026 contribution limit of $23,500.
Roth 401k vs Traditional 401k — The Core Difference
Traditional 401k contributions are pre-tax — you reduce taxable income now and pay ordinary income tax on all withdrawals in retirement. Roth 401k contributions are after-tax — you pay tax now and all qualified withdrawals (including gains) are completely tax-free. The 2026 contribution limit is $23,500 for both types combined (or $31,000 for employees 50+, and $34,750 for ages 60–63 under SECURE 2.0). Source: IRS Notice 2024-80. Last updated: May 2026.
Which One Wins? — The Tax Bracket Rule
| Situation | Choose | Reason |
|---|---|---|
| Current bracket > retirement bracket | Traditional | Save tax at high rate now, pay lower rate in retirement |
| Current bracket = retirement bracket | Either (or split) | Mathematically equivalent before TCJA/rate uncertainty |
| Current bracket < retirement bracket | Roth | Pay low rate now, avoid higher rate in retirement |
| Early career, low income | Roth | Decades of tax-free compounding on low-rate contributions |
| High income, near retirement | Traditional | Immediate tax deduction at 37% bracket |
SECURE 2.0 and 2026 Rule Changes
Starting in 2024, Roth 401k accounts eliminated RMDs — you are no longer forced to withdraw at age 73, unlike Traditional 401k. This makes Roth 401k ideal for estate planning: the tax-free balance can grow and transfer to heirs. Additionally, under SECURE 2.0, employer matching contributions can now be designated as Roth (after-tax), though they are taxable in the year contributed. These changes tilt the long-term advantage toward Roth for younger workers and those with strong estate planning needs.
Frequently Asked Questions
What is the 2026 401k contribution limit?
The 2026 401k contribution limit is $23,500 for employee elective deferrals. The catch-up for age 50+ is $7,500 (total $31,000). For ages 60-63 under SECURE 2.0, the catch-up is $11,250. Source: IRS Notice 2024-80.
When does Roth 401k beat Traditional 401k?
Roth 401k beats Traditional when your retirement tax bracket is equal to or higher than your current bracket. If you expect tax rates to rise, Roth is usually better. Traditional wins when your current bracket is significantly higher than your retirement bracket.
Does Roth 401k have RMDs?
Starting in 2024, Roth 401k accounts are no longer subject to Required Minimum Distributions under SECURE 2.0. This significantly improves Roth 401k's appeal for estate planning.
Can I do both Roth and Traditional 401k in the same year?
Yes. You can split contributions between Roth and Traditional within the same 401k plan, as long as the total does not exceed $23,500 in 2026. Employer matching is always Traditional regardless of your choice.
What happens if I convert Traditional 401k to Roth?
A Roth conversion triggers ordinary income tax on the converted amount in the year of conversion. Plan conversions strategically in low-income years — partial conversions over multiple years often reduce the tax bite.