Traditional vs. Roth 401(k) Comparison Calculator
Compare take-home pay today under a traditional versus a Roth 401(k) contribution.
This is an estimate for the 2026 tax year, not tax, legal, or financial advice. Figures are simplified and don't include every credit or deduction. Talk to a tax professional before making decisions.
How this is calculated
Both a traditional and a Roth 401(k) let you contribute the same dollar amount toward retirement, but they're taxed at opposite ends. A traditional contribution comes out of your paycheck before federal and state income tax, so it lowers your taxable income this year and gives you more take-home pay today — but the full withdrawal, including all its growth, is taxed as ordinary income when you take it out in retirement.
A Roth contribution comes out after tax, so it doesn't reduce your taxable income at all — it costs you more take-home pay right now. In exchange, qualified withdrawals in retirement, including all the growth, are completely tax-free.
We run the same salary, filing status, and state through the calculator twice — once contributing the amount to traditional, once to Roth — and compare the take-home pay each produces today. The traditional scenario will always show higher take-home pay today by exactly the tax it saves.
Neither option is strictly better. It generally comes down to whether you expect your tax rate to be higher or lower in retirement than it is right now: if you expect a lower rate later, traditional tends to win; if you expect a higher rate later — or want to lock in today's rate — Roth tends to win. This calculator only compares the near-term tax effect, not long-term investment growth.