Roth vs Traditional IRA calculator
See your after-tax retirement value side-by-side. The calculator reinvests the Traditional upfront tax deduction at the same return rate, then taxes withdrawals at your expected retirement bracket. Roth wins whenever your retirement rate is equal to or higher than your contribution rate.
| Years contributing | 35 |
| Total contributed | $245,000 |
| Gross balance at retirement | $967,658 |
| Same-dollar Traditional after withdrawal tax(Without reinvesting the deduction) | $735,420 |
The Traditional figure assumes you reinvest the upfront tax deduction at the same return and pay tax at the expected retirement rate. Without reinvesting the deduction, Traditional ends at $735K. Roth wins whenever your retirement rate is equal to or higher than your current rate, even before reinvesting the deduction.
How the math works
Roth
Final value equals annual contribution times the future-value annuity factor at your expected return for the years you contribute. Every dollar is yours tax-free at retirement, assuming age 59.5 and 5-year rule.
FVRoth = C * [((1 + r)n - 1) / r]
Traditional
Same formula for the gross balance, but every withdrawal is taxed as ordinary income. If you reinvest the upfront deduction at the same return, the Traditional account catches up only when your retirement rate is below your contribution rate.
FVTrad = (C * factor) * (1 - rateretire) + reinvested deduction
Limitations and what the calculator does not model
- Constant return. Real markets are volatile; 7% is a long-run S&P average, not a guarantee.
- RMDs not modelled. Traditional forces withdrawals at age 73, which can push you into higher brackets. See withdrawal rules.
- No state tax. Some states exempt Roth withdrawals; others tax Traditional withdrawals fully.
- No IRMAA. Medicare surcharges at MAGI over $103K (single) or $206K (MFJ) can hit Traditional retirees harder.