🧮 FIRE Calculator
How far is the finish line? Plug in your numbers and find out. Results update live — no signup, no spam, no judgment about the latte.
Your numbers
Projection 🚀
The fine print (light version)
This is a simple compound-growth model: monthly contributions, steady returns, no taxes, no market drama. Real life is bumpier — use it for direction, not prophecy. "Coast FIRE" means your current stash alone would grow to your FIRE number by age 65, even if you never saved another cent. Not financial advice — just campfire math. 🔥
Test your plan against thousands of possible market futures. Enter every amount in today's dollars; the planner handles inflation for you. Results update as you type.
👤 You
🛒 Spending & goal
🏦 Accounts & savings
Contributions rise with inflation and stop at retirement. In retirement the brokerage account is spent first, then the 401(k).
💵 Income streams
Rental income, Social Security, a pension, part-time work… Set the age each one starts (and stops, if it does). Enter after-tax yearly amounts in today's dollars. Untick "grows with inflation" for fixed payments like most pensions.
📈 Market assumptions
🎲 Thousands of possible futures
Portfolio value in today's dollars. Every simulated future traces its own path. The line is the middle one (half of the futures do better, half do worse), and the shaded bands show where most of them land. The wider the band, the more luck matters.
🧩 Where retirement money comes from
⏱️ Success rate by retirement age
🧪 Compare scenarios
Save your current inputs as a scenario, change something, then save again. Every scenario runs against the exact same simulated markets, so the differences come from your choices, not from luck.
| Scenario | Retire at | Spending | Success | At retirement | Left at end (median) | Left at end (worst 10%) |
|---|
How the Monte Carlo simulation works
- Each simulation steps through your life one year at a time, from your current age to your plan-until age. Results show the spread across all of them.
- Each year's market return is random, drawn to match your average return and volatility. You can set separate assumptions for before and after retirement.
- Inflation is random too. It varies around your average, and high-inflation years tend to come in runs, like they do in real life.
- Before retirement, your contributions go in and rise with inflation. Income you receive before retirement is assumed to already be part of your savings.
- In retirement, your inflation-adjusted spending is paid first by your income streams, then from the brokerage account, then from the 401(k). 401(k) withdrawals are increased to cover taxes, plus the 10% penalty before the access age. Any extra income is reinvested.
- A plan succeeds when spending is fully covered every year through your plan-until age.
- Not modeled: required minimum distributions, Roth conversion ladders, 72(t) payments, capital-gains tax on the brokerage account, possible Social Security benefit cuts, health-care cost spikes, and flexible spending rules. Treat the results as a guide, not a guarantee.
- Your inputs and saved scenarios stay in this browser only. Nothing is sent anywhere. Not financial advice, just campfire math. 🔥