Why Even the Best Retirement Calculator is Wrong
Why Even the Best Retirement Calculator is Wrong  
Podcast: Retirement Answer Man
Published On: Wed Mar 25 2026
Description: Roger Whitney explores why retirement planning software—especially Monte Carlo simulations—can give a false sense of confidence if misunderstood. He explains what these tools actually measure, the hidden assumptions behind them, and why retirement is a complex problem that requires judgment, flexibility, and resilience—not just a high “success rate.” Roger shares how to properly interpret results, avoid common traps, and use software as a guide rather than a decision-maker so you can build a retirement plan that supports a great life.OUTLINE OF THIS EPISODE OF THE RETIREMENT ANSWER MAN(00:00) This show is dedicated to helping you not just survive retirement, but have the confidence to lean in and rock it.(00:30) Roger introduces the episode topic—why your retirement calculator’s success rate can be misleading.PRACTICAL PLANNING SEGMENT(02:50) Roger explains his perspective as a long-time practitioner and outlines his experience using Monte Carlo-based retirement tools.(05:05) Complicated vs. complex problems: why retirement can’t be “solved” like a math equation and must instead be managed over time.(09:30) Concerns about overreliance on software—from advisors scaling businesses to individuals misinterpreting results.(11:30) What retirement software actually measures.(13:25) What software does NOT measure.(14:18) Best uses of planning software.(17:40) What software should NOT be used for.(19:40) Key dangers of using retirement software.(23:00) Feasibility vs. resilience: why a plan that “works” on paper may still be fragile in real life.(24:20) The real risk:Overspending early and jeopardizing later yearsUnderspending and missing out on life(26:20) The massive number of assumptions behind every plan—and how small changes can dramatically alter outcomes over time.(38:20) How to interpret results properly.(40:55) Looking beyond the number: evaluating the distribution of outcomes and plan sensitivity.(44:43) Understanding failures:Timing (early vs. late failures)Severity (minor shortfall vs. major gap)(48:27) Best practices:Hold success rates lightlyKeep plans simpleRegularly review assumptionsAvoid over-planning and constant tweakingDefine what success actually means for your lifeSMART SPRINT(56:04) Schedule time to review the assumptions in your retirement planning software—focus on understanding the inputs rather than optimizing the output.CLOSING THOUGHTS(56:50) Roger shares an update on the merger of his firm with Tanya Nichols’ firm and the creation of a new company, Retire Agile.REFERENCESlivewithroger.com — Register for Noodle Live on March 28!Submit a Question for RogerSign up for The Noodle