Monte Carlo Simulation for Retirement Success

Monte Carlo retirement simulation runs thousands of scenarios with randomized market returns based on your expected return and volatility. Instead of assuming a fixed return every year (which is unrealistic), it simulates various market conditions - good years, bad years, and everything in between. This gives you a probability distribution of outcomes rather than a single number, showing the likelihood of your retirement plan succeeding.

Success rate shows the percentage of simulated scenarios where your savings lasted through retirement. 90%+ = excellent, your plan is very robust. 75-90% = good, reasonable margin of safety. 50-75% = borderline, consider reducing spending or saving more. Below 50% = high risk of running out of money. These are probabilities based on historical market behavior patterns - they don't guarantee outcomes but provide valuable risk assessment.

Simple calculations assume constant returns, which is unrealistic. If you assume 7% average return and get -10% the first year, your plan fails. Monte Carlo simulates: 1) Sequence of returns risk (poor early returns can devastate portfolios), 2) Market volatility (up/down years affect final outcomes), 3) Multiple paths to retirement (not just one scenario). It reveals whether your plan survives bad luck, not just average conditions.

For accurate results, run at least 1,000 simulations - more is better but diminishing returns apply. Our calculator runs 1,000 scenarios, which provides statistically significant results for planning purposes. The key is understanding that Monte Carlo gives probabilities, not certainties. A 80% success rate means 1 in 5 scenarios fail - you should prepare for that possibility.