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Roth 401(k) vs Traditional 401(k) Tax-Equivalence Calculator

Compare after-tax balances at retirement; reports break-even tax rate.

Compare the after-tax retirement balance from contributing the same gross dollar amount to a Roth 401(k) (taxes paid now) versus a Traditional 401(k) (taxes deferred). Both grow at the same investment return; the better choice depends on whether your future tax rate is higher or lower than your current rate. Reports both balances and the break-even rate.

Nadia Almasri By Nadia Almasri
Published Last reviewed 1 min read

Inputs

$
yr
%
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%

Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

Roth: C·(1+r)ⁿ; Traditional after-tax: C·(1+r)ⁿ·(1−τ_future). Roth wins iff τ_future ≥ τ_now.

In depth

Compare the after-tax retirement balance from contributing the same gross dollar amount to a Roth 401(k) (taxes paid now) versus a Traditional 401(k) (taxes deferred). Both grow at the same investment return; the better choice depends on whether your future tax rate is higher or lower than your current rate. Reports both balances and the break-even rate.