When can you
stop working?
The most complete FIRE simulator in English. Project your financial independence with 5,000 parallel universes, country-specific taxes and historical data since 1950.
After 20 years
Not inflation-adjusted (nominal)
Purchasing power (real)
3,000 universes in your browser. No taxes or withdrawals. The full simulator adds taxes, couples and withdrawal strategies.
Open full simulator with these inputsFrom zero to your FIRE plan in 3 minutes
No credit cards, no sign-ups. Set things up, run the simulation and get your diagnosis instantly.
Set up your profile
Enter your current capital, monthly savings, target age and portfolio allocation. The quick wizard simplifies everything if you're in a hurry.
Run the simulation
Our C++ engine runs 5,000 parallel universes in your browser using real historical data. Your full diagnosis is ready in seconds.
Interpret and adjust
Analyze the three scenarios (pessimistic, base, optimistic), the risk of ruin and the automatic diagnosis of your plan.
How long until you reach your goal?
Indicative estimate using compound interest (fixed return). For volatility, taxes and P10/P50/P90 scenarios, use the full simulator.
Estimated time (deterministic scenario)
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Excludes volatility and taxes. For guidance only.
Everything you need to plan your FIRE journey
Designed by and for European investors. Supports couple plans, dynamic glidepath, stress events and country-specific tax modelling.
Monte Carlo + Historical
Combines classic stochastic simulation with historical bootstrapping from the Jordà-Schularick-Taylor database.
Country-specific tax
Progressive capital-gains brackets out of the box for Spain, USA, UK, Germany, France, Italy and more.
Couple plans
Simulate the savings and withdrawal flows of both partners with independent ages, pensions and inheritances.
Dynamic portfolio (glidepath)
Smoothly transition across allocations over time — Bond Tent strategy included.
Withdrawal strategies
Classic 4% rule, Guyton-Klinger with guardrails and Variable Percentage Withdrawal (VPW).
Coast / Barista / Flamingo
Quick presets to simulate FIRE variants without reconfiguring the entire plan by hand.
Real estate and debt
Add rentals, mortgages and personal loans with month-by-month payment or upfront payoff strategies.
Stress events
Inject market crashes in specific years to validate the resilience of your plan against severe crises.
Academic rigour, not naive estimates
Traditional calculators assume fixed returns. Reality is volatile. That's why this simulator generates thousands of trajectories with real data.
- Jordà-Schularick-Taylor database (London School of Economics / Berkeley)
- Markowitz's Modern Portfolio Theory for correlations
- Historical Block Sampling 1950-2020 (modern era)
- C++ engine — 5,000 trajectories in seconds
- Real FIFO tax accounting, not simplistic averages
What people usually ask
Is it really free? Is there a paid version?
Yes, completely free with no sign-up. There's no hidden paid tier either. If you want to save simulations in the cloud and use the AI advisor you can sign in with Google, but every calculation feature is available without an account.
What's the difference between pure Monte Carlo and historical mode?
Custom mode generates random returns from a normal (Gaussian) distribution with the mean return and volatility you define. Historical mode extracts real years from 1950-2020 while preserving the correlation between stocks, bonds, inflation and exchange rates. Both are useful, but historical is the institutional standard to validate retirement plans.
Is my data stored or sent to any server?
Not by default. The simulation runs in your browser via WebAssembly compiled from C++. Only if you choose to save a plan or request an AI diagnosis do we send the data encrypted to our servers (Supabase + Gemini).
Which countries does the tax modelling cover?
Built-in templates for Spain, USA, UK, Germany, France, Italy, Portugal, Ireland, Switzerland, Austria and Sweden, all with editable progressive brackets. You can also enter manual rates if your jurisdiction isn't on the list.
What do the P10, P50 and P90 percentiles mean?
P50 is the median scenario: half of the simulations end with more capital and half with less. P90 represents a strongly bullish market (only 10% of scenarios were better). P10 is the pessimistic scenario — a lost decade of crises. If your plan survives P10, it's exceptionally robust.
Your financial independence starts now
Three minutes to find out whether your FIRE plan really works. No commitments, no sign-ups, no credit cards.
Start free simulationRuns 100% in your browser · We don't store your data without your permission