Early Retirement Withdrawal Calculator

Each simulation month updates your portfolio using: Portfolio = Portfolio × (1 + monthly_return) − monthly_withdrawal. The monthly return and monthly inflation rate are randomly sampled from your selected scenario (or your custom inputs), with correlation supported between returns and inflation. Your withdrawal amount changes by strategy: fixed nominal stays constant, inflation-adjusted grows with inflation, and guardrails adjust dynamically based on recent stress.

With the inflation-adjusted strategy, withdrawals rise as modeled inflation rises, which can increase ruin risk during high-inflation paths—even if average returns look fine. Fixed nominal may show a higher success probability in simulations, but it can quietly erode purchasing power, meaning you might not sustain the same lifestyle in real terms. Guardrails can reduce sequence-risk by cutting withdrawals when the portfolio is under pressure, then allowing recovery within bounds.

This tool excludes taxes, fees, required minimum distributions, and Social Security—so real-world outcomes may differ. It also assumes stable return and inflation behavior over time (no major regime shifts) and no additional contributions or one-time expenses. Most importantly, you’ll need to set (or align on) a retirement horizon in the calculator UI, because survival probability depends directly on how long withdrawals continue.

If starting funds are 0 (or close to it), success probability will be near zero unless spending is also 0. If retirement spending exceeds the starting portfolio, the tool still simulates (you may still succeed with a very short horizon), but you should expect a high chance of rapid ruin. For guardrails, withdrawals are bounded (no negative withdrawals by default), so spending won’t automatically “flip” into contributions when markets crash.