Roth vs Traditional 401k Calculator (2026) — Which Wins for You?
Compare Roth vs Traditional 401k after-tax retirement income based on your tax brackets. See the winning strategy for your income — updated for 2026 IRS contribution limits.
What is a Roth or 401k Calculator?
A Roth or 401k calculator is a comparison tool designed to determine which retirement account yields the highest after-tax income. A Traditional 401k provides an upfront tax break but taxes withdrawals in retirement. A Roth 401k applies taxes immediately, offering entirely tax-free withdrawals later. This calculator assumes equal out-of-pocket costs to provide a mathematically accurate comparison.
The Winning Strategy for You
Roth vs Traditional 401(k) Definitions
Choosing between a Roth 401(k) and a Traditional 401(k) is one of the most important decisions you can make for your retirement strategy. The choice dictates whether you pay the IRS today or later in life. Our premium Roth vs Traditional 401k calculator projects your net take-home cash to find the winner. Here is what you need to know:
Traditional 401(k)
Traditional contributions are made with pre-tax dollars. This lowers your current taxable income, saving you money on taxes today. However, your money grows tax-deferred, meaning you will have to pay standard income taxes on every dollar you withdraw during retirement.
Roth 401(k)
Roth contributions are made with after-tax dollars. You get no immediate tax deduction today, which means it costs more "out of pocket" to invest the same amount. The massive benefit is that your investments grow entirely tax-free, and you owe the IRS absolutely nothing when you withdraw the funds in retirement.
Current vs Retirement Tax Brackets
Your tax bracket is the deciding factor. If you are in a low tax bracket right now but expect to be wealthy and in a high tax bracket during retirement, the Roth 401(k) is vastly superior. Conversely, if you are currently in your peak earning years facing massive taxes, a Traditional 401(k) provides vital immediate tax relief.
Annual Out of Pocket
This represents the actual reduction in your paycheck caused by your investment. Because a Traditional 401(k) lowers your taxes today, a $10,000 "out of pocket" reduction in your paycheck actually allows you to invest a higher gross amount (e.g., $12,500) into your account.
Roth vs. Traditional 401k FAQ
Choose Roth 401k if you are in a lower tax bracket now and expect to be in a higher bracket in retirement (most common for younger, early-career workers). Choose Traditional 401k if you are in your peak earning years and want an immediate tax deduction. Our calculator models your exact scenario. See IRS 401k plan rules.
For 2026, the IRS contribution limits for both Roth and Traditional 401k are identical: $23,000 under age 50 and $30,500 for ages 50+ (including $7,500 catch-up). You can split contributions between Roth and Traditional up to this combined limit.
A Roth 401k is typically best for anyone in the 12% or 22% tax bracket who expects to retire at a higher income level. Young professionals and early-career workers especially benefit from decades of tax-free compound growth. If you are in the 32%+ bracket, Traditional is usually superior.
Roth 401k contributions are made with after-tax dollars. Since you have already paid income tax on those funds, all growth and qualified withdrawals in retirement are 100% tax-free. You will never owe the IRS taxes on that money again.
Yes, if your employer plan offers both options. This "tax diversification" strategy means you can split contributions between Roth and Traditional up to the combined 2026 IRS limit. In retirement, you can choose which bucket to draw from based on that year's tax situation.
You can redirect your future contributions to Roth at any time by updating your plan elections. To convert an existing Traditional 401k balance to Roth, your plan must allow an in-plan Roth conversion, which creates a taxable event in the year of conversion.
Roth vs Traditional 401k: Which Wins at Your Income Level?
Your current tax bracket is the decisive factor. Here is a quick reference guide based on 2026 IRS tax brackets (IRS Topic 409):
| Annual Income | Tax Bracket | Recommended |
|---|---|---|
| Under $44,725 | 12% | Roth 401k |
| $44,725 – $95,375 | 22% | Roth 401k |
| $95,375 – $182,050 | 24% | Mixed / Evaluate |
| $182,050 – $231,250 | 32% | Traditional 401k |
| $231,250+ | 35–37% | Traditional 401k |