Static plans for a dynamic life
Your life evolves — sometimes in ways you plan, and sometimes in ways you don't.
Maybe you're thinking about switching jobs, starting a family, or moving to a new city. Or maybe you just want to explore whether selling your RSUs or renting instead of buying makes more sense.
You need a FIRE tool that grows with you — without making you start from scratch or pay extra for every “new” plan.
Most tools or spreadsheets assume a straight path from now to retirement, no big life changes, and no tough tradeoffs to evaluate.
Without scenario planning, you're either planning blindly — or not planning at all.
MOF gives you the flexibility to model real-life decisions and see how they impact your FIRE plan.
Adjust income, expenses, and goals. Want to cut expenses by 10%? Model a one-time splurge? Test an income boost or pay cut? Just enter your assumptions and MOF does the rest.
MOF lets you run scenarios — fast, flexible, and unlimited
Explore how different assumptions affect your plan. Each scenario compares your current plan against alternatives — showing living expenses, retirement expenses, FI date, and FI number side by side.
Instantly see the tradeoffs
Every change shows immediate updates to your FIRE date, FI number, and the actions to get there.
Six dimensions of analysis
Expenses, income growth, market returns, withdrawal rate, working longer, and RSU performance — all generated automatically.
Stacked scenarios
Model compound changes like getting a raise and funding college, or taking a sabbatical and delaying FIRE.
Historical stress testing built in
Scenario planning tells you what could happen if your life changes. Historical stress testing tells you whether your plan would have survived the worst markets in history. MOF does both automatically.
155+ historical scenarios, 1871 to present
Your retirement plan is tested against every overlapping period in market history using Robert Shiller's dataset of S&P 500 total returns, Treasury bond yields, and actual inflation. No synthetic Monte Carlo assumptions — real market data from the Great Depression, 1970s stagflation, the dot-com crash, and the 2008 financial crisis.
Know your success rate
See the percentage of historical periods where your portfolio would have lasted your entire retirement. If your success rate is below your comfort level, adjust your plan and rerun instantly.
See exactly which periods would fail
When your plan falls short, MOF shows the specific historical start years that caused failure — like retiring in 1929 or 1966 — and how long the portfolio would have lasted. You can assess whether those tail risks matter to you.
Portfolio trajectory percentiles
A fan chart shows your portfolio's projected path at the 10th, 25th, 50th, 75th, and 90th percentiles across all historical scenarios. See the range of possible outcomes — not just a single average — so you understand the spread of risk.
Automated sensitivity analysis
Beyond historical backtesting, MOF automatically generates “What If?” analysis across six dimensions:
- Expense reduction — what if you spend less in retirement?
- Income growth — faster or slower salary trajectory
- Market returns — sensitivity to different return assumptions
- Safe withdrawal rate — impact of 3% vs 4% vs 5%
- Working longer — 1 to 3 additional years of income
- RSU performance — company stock growth scenarios
No configuration needed. Enter your financial profile once. MOF runs all 155+ historical backtests and six sensitivity analyses automatically — every time you calculate.
FAQ
A: As many as you want. MOF is designed for fast, iterative planning so you can explore freely.
A: Yes — you can save, title, and revisit them anytime to compare or update as your life evolves.
A: Almost anything: income changes, kids' education, housing, RSUs, expenses, and more.
A: Your plan is tested against every overlapping retirement period from 1871 to present using actual stock returns, bond yields, and inflation from Robert Shiller's dataset. Each scenario simulates whether your portfolio would survive your full retirement.
A: No. Monte Carlo uses randomly generated returns. MOF uses actual historical market data — real sequences of returns that actually happened — which captures correlations and tail risks that random models can miss.
Plan for every possibility
Your FIRE plan should be as dynamic as your life. Model any scenario and see exactly how it affects your path.
Start my scenario plan