#636 - Why Even the Best Retirement Calculator is Wrong
💬 Show Notes
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 years
Underspending 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 lightly
Keep plans simple
Regularly review assumptions
Avoid over-planning and constant tweaking
Define what success actually means for your life
SMART 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.
REFERENCES
livewithroger.com — Register for Noodle Live on March 28!