Will my portfolio survive retirement?

10,000 market simulations with inflation-adjusted withdrawals show your probability of never running out of money — the analysis advisors keep behind paid tools, free.

Current age

Life expectancy (age)

Portfolio balance ($)

First-year withdrawal ($/yr)

Average annual return (%)

Return volatility (std, %)

Inflation (%)

Simulations

—

Survival probability

—

Median ending balance

—

10th percentile (bad case)

—

Withdrawal rate (initial)

What does a Monte Carlo simulation do?

It runs thousands of plausible histories — each year randomly drawn from a lognormal return with your mean and volatility — and asks how many histories never hit zero with inflation-adjusted withdrawals. That share is your survival probability.

Why is 4% not a guarantee?

4% survived ~95% of historical 30-year windows (Trinity Study). This tool uses your own current-market assumptions: 10,000 paths at 7% mean / 12% vol with 40-year horizons often shows a different number — usually lower. That's the honest answer.

What is the 10th percentile telling me?

The bad-but-plausible outcome: 90% of simulations ended above this balance. If it's near zero, your plan depends on good luck; consider a lower withdrawal rate.

Why does the result change each load?

Each calculation draws new random paths. Run it a few times — the probability should move only a fraction of a percent; that variability is the tool being honest about randomness. (For the exact same answer every time, check the FAQ seed — not included for simplicity.)