Monte Carlo retirement calculator

1,000 seeded paths, a success rate, and a band of ending balances. No account. The live demo is the full household engine; this page is one identity.

The calculator

Success rate54%
10th percentile ending$0
Median ending$141,920
90th percentile ending$3,189,156

Versus the live demo

This band is independent lognormal draws around the mean you typed. The live Monte Carlo demo uses Killion’s five-regime engine, an allocation, and a crash you can place. The methodology page is the product model. How to read a Monte Carlo is the explainer.

Assumptions

1,000 paths, seed 20260828, 15% volatility, start-of-year withdrawals. Not a forecast.

Frequently asked questions

What is a Monte Carlo retirement calculator?
A tool that runs a withdrawal plan through many random market sequences and reports how often the money lasted, instead of one path from an average return.
How is this different from the live demo?
This page is one identity: a portfolio, a spend, a horizon, a lognormal band. The demo runs the full household engine — five regimes, allocation, crash year — on a fictional household.
Try the live demoStart a 5-day free trial