Traditional vs Roth 401(k) Calculator
Compare a Traditional and Roth 401(k) on what you actually keep after tax, held to an equal take-home cost.
Want to understand the concept, not just the number? Read Traditional vs Roth 401(k) .
How it's calculated
The choice between a Traditional and a Roth 401(k) comes down to one thing. Do you pay tax now or later. A Traditional contribution is pre-tax, so it lowers your tax bill today, and you pay tax when you withdraw in retirement. A Roth is the reverse. You pay tax now, and qualified withdrawals later are tax-free. The winner depends on whether your tax rate is higher now or in retirement.
This compares them fairly by holding your out-of-pocket cost equal. Take the default. Putting $10,000 of pre-tax income a year toward retirement at a 7 percent return for 30 years. In a Traditional account the full $10,000 goes in and grows to about $944,608, then a 22 percent retirement tax leaves $736,794. In a Roth, the same take-home cost means only $7,600 goes in after 24 percent tax now, growing tax-free to $717,902. Here the Traditional wins by about $18,892, because the retirement rate is lower than today.
Flip the rates and the answer flips. If you expect a higher tax rate in retirement, the Roth wins, since you lock in today rate and never pay tax on the growth. Roth also has no required minimum distributions and gives valuable tax flexibility later. When the two are close, many people split contributions between both to hedge which way rates go.
Assumptions
- Holds your take-home cost equal. The pre-tax amount funds the Traditional in full, and the Roth receives it minus tax at your current rate.
- Uses level annual contributions and one steady return. It does not model separately investing a Traditional tax refund or future limit changes.
Last updated: 2026-08-08
These assumptions follow our general methodology.
Frequently asked questions
Traditional or Roth 401(k), which is better?
Roth wins if your tax rate will be higher in retirement than today. Traditional wins if it will be lower. If you are unsure, splitting between the two hedges the risk, since you cannot know your future rates for certain.
How does this compare them fairly?
By holding your take-home cost equal. The full pre-tax amount goes into the Traditional, while the Roth gets what is left after paying tax now. That is the honest comparison, since a dollar in a Roth costs more than a dollar in a Traditional.
Does a Roth 401(k) have income limits?
No. Unlike a Roth IRA, a Roth 401(k) has no income limit, so high earners can contribute directly. The employee limit, $24,500 in 2026, is shared across Traditional and Roth 401(k) contributions.
Is the employer match Traditional or Roth?
Employer matching has historically gone into the Traditional side and is taxed at withdrawal, though some plans now allow a Roth match. Either way, the match is free money worth capturing. See the 401(k) Match calculator.