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Roth vs Traditional Calculator

Adjust the inputs below. Results update as you type.

How it works

Traditional 401(k)/IRA contributions reduce taxable income now but are taxed at withdrawal. Roth contributions are after-tax but grow and withdraw tax-free. If your tax rate is lower now than in retirement, Roth wins. If higher now, traditional wins. Most people benefit from having both types for tax diversification in retirement.

Input guidance

  • Use realistic rates from lender or provider quotes instead of headline averages.
  • Model conservative, baseline, and optimistic scenarios before deciding.
  • Include recurring real-world costs (fees, taxes, insurance, maintenance) where relevant.

More examples to test

  • Conservative case: use a higher interest rate and lower growth assumptions to stress-test affordability.
  • Optimistic case: use a lower rate with stable income assumptions to compare upside potential.

How to interpret results

Treat this as a planning model, not a final approval tool. Compare at least two scenarios and focus on total-cost and cash-flow trade-offs.

When this can be inaccurate

Results can diverge due to fees, changing rates, tax rules, lender policies, and behavior changes that simplified models cannot fully capture.

Change history

  • July 2026: Quality-reviewed for publication with formula checks and explanatory copy updates.

Site-wide corrections also appear on the corrections log.

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Frequently asked questions

How should I use this result?+

Treat it as a planning estimate. Compare at least two realistic scenarios, then confirm with statements, quotes, or a qualified professional before acting.

How often should I refresh assumptions?+

Refresh whenever rates, income, costs, or policy limits change materially, and before making irreversible commitments.

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