Roth vs Traditional 401(k) Calculator 2026 β Which Is Better?
Compare Roth and Traditional 401(k) side-by-side. See current tax savings vs retirement balance and find out which strategy wins for your situation.
Side-by-Side Projection (10-Year Snapshots)
| Year | Trad. Balance | Trad. After-Tax | Roth Balance | Roth Advantage |
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How This Roth vs Traditional 401(k) Calculator Works
Enter your salary, contribution rate, and tax rates. The calculator computes the after-tax value of each strategy at retirement. Traditional contributions reduce your taxable income now but are taxed at withdrawal. Roth contributions cost more today (after-tax dollars) but grow completely tax-free.
Calculation Logic
Traditional: pre-tax contribution, no upfront tax cost
β FV = Contribution Γ [(1+r)^n β 1] / r
β After-Tax = FV Γ (1 β Retirement Rate)
Roth: after-tax contribution cost = Contribution Γ (1 β Current Rate)
β FV = same as Traditional (same contribution amount)
β After-Tax = FV (100% tax-free)
Example
Both strategies grow to same pre-tax FV: ~$607,000
Traditional after-tax: $607,000 Γ (1 β 18%) = $497,740
Roth: $607,000 (fully tax-free)
Roth wins by: $109,260 β the lower retirement rate still doesn't overcome tax-free compounding
Breakeven Tax Rate Analysis
At what future tax rate does Roth become better than Traditional? Sensitivity table across all brackets.
At what future retirement tax rate does each strategy win? The table shows after-tax retirement value for both Roth and Traditional across all common future tax rates. Uses the salary and contribution rate entered above.
After-Tax Retirement Value by Future Tax Rate
| Future Tax Rate | Traditional After-Tax | Roth Tax-Free | Roth Advantage | Winner |
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