Typed 401l? The l and k sit side-by-side on the keyboard — you’re in the right place for a free 401(k) calculator.

Disclaimer

This site is for educational and informational purposes only. Nothing on 401lcalculator.com constitutes financial, tax, legal, investment, or retirement-planning advice.

Your Money, Your Life. 401(k) and retirement decisions are high-stakes. This site cannot replace personalized advice from a licensed professional who knows your complete financial situation.

Not Financial Advice

We are not registered investment advisors, certified financial planners, tax attorneys, or accountants. We do not hold any fiduciary relationship with you. The calculators, articles, FAQ entries, and tables published on this site are general educational content only. Do not rely on them as the sole basis for any financial decision.

Before making any 401(k), tax, or retirement decision, you should consult at least one of the following: a Certified Financial Planner (CFP®), an IRS Enrolled Agent, a CPA, or a licensed attorney admitted in your state.

Past Performance Is Not a Guarantee of Future Results

Several tools on this site reference the S&P 500 historical average real return of approximately 7% per year (1957–2024). This figure is a statistical average over a long period that included multiple recessions, a 50%+ drawdown in 2008–09, and the 2020 pandemic crash. Your own investment return could be materially lower (or higher). In any given 10-year window, historical US equity returns have ranged from deeply negative to more than 15% annualized.

Accuracy of IRS & Tax Data

All contribution limits, catch-up amounts, RMD divisors, and bracket figures come directly from IRS publications and related statutes. Despite our best efforts, we may contain typographical errors or fail to update within hours of an IRS notice. Always verify critical numbers against the IRS website before acting on them.

Calculator Methodology & Assumptions

  • Compound growth is calculated semi-annually on the starting balance; new contributions earn half a year of growth on average.
  • Employer match is modeled as an annual amount based on your contribution rate, subject to the IRS Section 415 combined limit ($70,000 in 2026).
  • Catch-up contributions apply automatically based on age (50+ or 60–63 under SECURE 2.0).
  • Taxes on withdrawals use 2026 federal brackets and simplified top marginal state tax rates. These are estimates, not tax-return-accurate figures.
  • Fees are not modeled. A typical mutual fund or target-date fund can reduce returns by 0.10–1.50% per year. Model your own expense ratio if relevant.
  • Inflation is applied uniformly at your chosen rate; real-world CPI is volatile.
  • All calculations run entirely in your browser. No user input is transmitted to our servers or third parties.

Third-Party Links

We link to IRS, SSA, FRED, CFP Board, and other authoritative external sources. We do not endorse any third-party site’s content, and we are not responsible for its accuracy, terms, or privacy practices.

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Limitation of Liability

By using this site, you agree that the site’s author, publisher, and any contributors are not liable for any loss or damage arising from your use of or reliance on any content, calculator output, or recommendation presented here. Use at your own risk.

Contact

For corrections, feedback, or reprint requests, contact David Jones via our contact page or mail: 3069 Oak Ln, Juneau, AK 99801.

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