401k vs Roth IRA calculator
Most calculators compare Roth versus Traditional. This one compares 401k versus Roth IRA the way the question is actually asked, with the employer match modelled in. Uses 2026 IRS contribution limits: $24,500 employee deferral (26 U.S.C. § 402(g)), $7,500 Roth IRA (26 U.S.C. § 408A(c)(2)), $8,000 catch-up at 50+ (26 U.S.C. § 414(v)), $11,250 SECURE 2.0 enhanced catch-up at 60-63 (26 U.S.C. § 414(v)(2)(E)).
Project your retirement balance
Employer dollars compounded at 7%. Skip the match and this is the number you leave behind. Output uses 2026 IRS limits, including age based catch ups (50 plus) and the 60 to 63 super catch up.
What the three scenarios mean
Each scenario uses identical inputs (age, salary, raise, return, retirement age, retirement tax rate) and changes only what the contributions are.
401k only, max contributions
You fund the 401k up to the legal cap each year. The match is captured. There is no Roth IRA. Pre tax growth is taxed on withdrawal at the retirement rate you set.
Roth IRA only, no match
You fund only the Roth IRA. There is no 401k contribution and the match is left on the table. Growth and qualified withdrawals are tax free.
Match plus max Roth IRA
You contribute exactly the percentage needed to capture the full employer match in the 401k, then fully fund the Roth IRA. This is the recommended starting position.
What this calculator does and does not include
- 2026 IRS Notice 2025-67 contribution limits (§ 402(g) $24,500 / § 408A(c)(2) $7,500)
- Age-based catch-ups (§ 414(v) at 50+ / § 414(v)(2)(E) SECURE 2.0 enhanced at 60-63)
- Employer match modelled as a percentage of contributions up to a salary cap (against § 415(c) ceiling)
- Annual raise compounded into salary, increasing absolute match dollars
- Single retirement tax rate applied to pre-tax balances at withdrawal under § 72
- Inflation adjustments (use a real return such as 4-5% if you prefer)
- State income taxes in retirement
- Plan fees disclosed under 29 CFR 2550.404a-5 (look at your annual statement)
- Sequence-of-returns risk and market volatility
- IRMAA Medicare surcharges on Traditional distributions
- Future legislative changes to § 402(g), § 415(c), or § 408A limits
Where each milestone falls on the runway
Calculator questions
How accurate is a 401k vs Roth IRA calculator?+
Any retirement projection is an estimate. This calculator applies real 2026 IRS limits per IRS Notice 2025-67, age-based catch-ups under 26 U.S.C. § 414(v), and a configurable rate of return, then projects compounded balances and applies your chosen retirement tax rate. Real outcomes depend on actual returns, plan fees disclosed under 29 CFR 2550.404a-5, future limit changes, and personal circumstances. Calculator outputs are estimates, not forecasts. See /disclaimer.
What rate of return should I use?+
A 7% inflation-adjusted return is a common default for diversified equity portfolios over multi-decade periods. More conservative portfolios run lower (4-5%) and a 100% equity tilt may run higher. Stress-test with 5% and 8% to see the range of plausible outcomes. The calculator does not model sequence-of-returns risk or the impact of 29 CFR 2550.404a-5-disclosed plan fees.
Why does the optimal scenario only put the match into the 401k?+
The optimal scenario captures every dollar of employer match in the 401(k) (which sits against the 26 U.S.C. § 415(c) $72,000 combined cap, not the § 402(g) $24,500 employee cap), then fully funds the Roth IRA up to the § 408A(c)(2) $7,500 limit. If you have additional savings beyond those two steps, route the rest back into the 401(k) toward the $24,500 § 402(g) cap. The result is a tax-diversified mix.
Do you account for the SECURE 2.0 super catch up?+
Yes. The model uses age-based 2026 IRS limits from IRS Notice 2025-67: $24,500 base under 26 U.S.C. § 402(g), $32,500 at age 50+ under 26 U.S.C. § 414(v), and $35,750 for ages 60-63 under SECURE 2.0 § 109 (26 U.S.C. § 414(v)(2)(E)). Roth IRA limits step from $7,500 to $8,600 at age 50 under 26 U.S.C. § 219(b)(5)(B).
Does the calculator model the mega backdoor Roth?+
No. The mega backdoor Roth uses voluntary after-tax 401(k) contributions against the 26 U.S.C. § 415(c) annual additions cap ($72,000 in 2026), then converts to Roth via in-plan conversion under 26 U.S.C. § 402A(g) (SECURE 2.0 § 604) or in-service distribution per IRS Notice 2014-54. See /mega-backdoor-roth for the dedicated walkthrough.