Run Your Roth vs Traditional 401(k) Numbers Today
Use our Roth vs Traditional 401(k) Calculator to instantly compare after-tax retirement balances and make smarter contribution decisions in seconds.
401(k) Contribution Planner
Balances at Retirement
Frequently Asked Questions
See exactly how much more your Roth 401(k) could be worth at retirement. Compare tax scenarios side-by-side with our free, fast 401(k) calculator.
A: The calculator compares two numbers that matter most: your nominal balance at retirement and your after-tax withdrawal value. A Traditional 401(k) grows pre-tax but gets taxed on withdrawal. A Roth 401(k) grows tax-free. Same contribution, different real-world outcome — this tool shows you exactly how big that gap is.
A: This is the deciding variable. If your current tax rate is higher than your expected retirement tax rate, the Traditional 401(k) wins — you defer taxes to a lower bracket. If your retirement rate stays the same or rises, the Roth 401(k) delivers more after-tax value. The calculator lets you test both scenarios in real time by adjusting both sliders.
A: Multiply your nominal balance by (1 − retirement tax rate). Example: a $2,218,702 balance at a 22% retirement tax rate yields $1,730,587 after taxes — exactly what the calculator displays. Roth balances carry no tax on withdrawal, so $2,218,702 in a Roth stays $2,218,702.
A: At $50,000 annual income, most earners sit in the 22% federal bracket. If you expect to retire in the same or a lower bracket, the Traditional 401(k) offers a small tax arbitrage edge now. But for FIRE-focused savers who plan to retire early with flexible withdrawals, Roth wins — no required minimum distributions (RMDs) and zero tax on gains.
A: The calculator uses your custom annual contribution input — it doesn't cap you automatically. For 2025, the IRS 401(k) contribution limit is $23,500 (plus $7,500 catch-up if you're 50+). Enter your actual planned contribution to get accurate projections.
A: The calculator uses your current age and target retirement age to determine the compounding period. Set age 30 with retirement at 65 and you get 35 years of compounding at your chosen rate of return. Adjust the retirement age slider to instantly see how retiring at 55 vs 65 changes your balance.
A: The 7% annual return is the standard real-return benchmark for diversified equity portfolios after accounting for historical inflation, widely used by financial planners. It's a reasonable baseline — not a guarantee. The calculator lets you test 5%, 8%, or any custom rate to stress-test your retirement outcome.
A: Absolutely. Set your retirement age to 45, 50, or 55 and see how aggressive contributions compound over a shorter horizon. For FIRE planning, Roth 401(k) has a structural advantage: no RMDs, and contributions (not earnings) can be accessed penalty-free after 5 years via Roth conversion ladders. The calculator gives you the starting balance figure your FIRE plan needs.