Mission Planner
Plan your path in phases
Real plans aren't one formula: work hard for a while, coast, go part time, take a break, then retire. Lay out your phases and see how they hold up in good and bad markets.
Free, no account needed. Everything runs in your browser, and OrbitFire never sees your numbers.
How the simulation works
Each simulated market draws a different return for every year, centered on your expected return after inflation, with swings sized to your stock share (about 15% a year for all stocks, 12% at 80/20 and 9% at 60/40). Returns follow a bell curve on a log scale, so a few years are very good and a few are very bad. The same plan always gets the same 1,000 markets, so changes you make are the only thing moving the result.
Instead of a single success score, the results tell you what a bad market would ask of you: how much to trim spending, or that you'd want to work a little longer. Research on retirement spending shows that people who adjust in bad years rarely run out.
Simulations are a model, not a forecast. Taxes and Social Security are not included. For education and planning, not financial advice.