Roth vs Traditional 401k Calculator

Same paycheck deferral can land differently — enter contribution, years, return, and tax rates now vs in retirement. Click any i for detail.

Deferral compare

Annual gross deferral ($) i Deferral Same paycheck amount directed to either account type.
Years to grow i Years Years until retirement withdrawal.
Expected return (%) i Return Average annual investment return.
Current marginal tax (%) i Current tax Tax on Roth contribution (after-tax slice).
Retirement tax (%) i Retirement tax Tax on traditional withdrawals.

Headline shows the higher after-tax balance side on your inputs; breakdown lists both futures.

Tax timing difference.

Item	Detail
Traditional	Pre-tax grow, taxed at withdrawal
Roth	After-tax contrib, tax-free growth sketch

Employer match, state taxes, and Social Security taxation not modeled.

Traditional after-tax = gross deferral × (1+r)^n × (1 − retirement tax). Roth after-tax = net deferral × (1+r)^n.

$12k deferral for 25 years at 6% with 24% now and 18% later can favor Roth or traditional depending on rate gap.

What about employer match?

Match is usually pre-tax traditional — not split here.

State taxes?

Use rates that fit your state situation in the fields.

Roth always better?

Depends on tax rate now vs later — this tool compares your inputs.