Roth vs. Pretax Calculator

The real comparison comes down to one thing: your tax rate now versus your tax rate later.

Annual contribution ($)

Years until withdrawal

Expected annual return (%)

Your current marginal tax rate (%)

Expected marginal tax rate in retirement (%)

Roth path — net after-tax value

—

Pretax path — net after-tax value

—

Educational estimate, not tax advice — this model assumes the pretax path's current-year tax savings get reinvested at the same return, ignores state taxes, ignores RMD-driven bracket effects, and treats your future marginal rate as a single guess. When current and expected retirement rates are equal, the two paths are mathematically identical — Roth only pulls ahead when you expect your retirement bracket to be higher, not lower, than today's.