Your numbers
2026 IRA limit is $7,000 · 401(k) limit is $23,500. Enter what you'll actually contribute each year.
Tax brackets
Not sure? Most people retire in the 22-24% bracket. If you expect lower income in retirement, traditional tends to win. If you expect higher, Roth does.
The winner, after-tax
Roth wins
By $30,787 at retirement — comparing the after-tax nest egg, with traditional's annual tax savings reinvested in a taxable account at 7%/yr.
Roth IRA after-tax
$711,650
No tax on exit
Traditional after-tax (incl. reinvested savings)
$680,862
Taxed at 24% on withdrawal
After-tax projected value
Pre-tax balance
$711,650
Same in both accounts — only tax treatment differs
Tax savings (traditional)
$46,200
Deduction reinvested at market return
Edge
+$30,787
Roth's after-tax advantage
The one rule that actually matters
If your current tax rate is higherthan your expected retirement rate → traditional. If it's lower→ Roth. If they're the same, it's a wash on the math — so pick Roth for the tax diversification and no-RMDs perks.
Show the mathExpand →
We compound the same annual contribution monthly in both accounts. Pre-tax balance is identical — the fork is at withdrawal.
Roth: after-tax balance = pre-tax balance (no tax on qualified withdrawals).
Traditional: after-tax balance = pre-tax balance × (1 − retirement rate). The annual deduction saved in the current year is invested in a taxable account at the same return rate; gains taxed at 15% long-term cap-gains on exit.
We don't model state tax, RMDs, Social Security taxability, or Roth conversion ladders. The break-even is primarily a tax-bracket question — everything else is rounding.
Why this comparison is honest
Same dollars, same growth
Both accounts receive identical annual contributions growing at the same market return. The pre-tax balance is literally the same number. The fork is at withdrawal.
Traditional's tax savings get reinvested — fairly
Most calculators ignore the deduction. We invest it in a taxable account at the same return, then tax the gains at 15% long-term cap-gains. That's how real people actually deploy it.
The one rule that matters
Current bracket lower than retirement bracket → Roth. Higher → Traditional. Same → Roth for tax diversification (and no RMDs). Everything else is rounding.