Monte Carlo simulation is a technique that runs thousands of independent trials — each with randomly drawn market returns — to produce a probability distribution of outcomes rather than a single projection. Retirement Lab runs 10,000 simulated market paths for each scenario.
Retirement Lab models income tax, capital gains tax, and wealth tax across 26 supported countries, including the US, UK, Canada, Spain, Portugal, France, Germany, and more.
Tax calculations use real bracket-based models with current published rates. They are simplified approximations — consult a qualified tax professional for your specific situation.
No. Retirement Lab is a financial calculator. All results are hypothetical projections based on your inputs and assumptions.
The full Monte Carlo simulator is free for everyone. The 30-day Pass ($30 once) unlocks all Pro features for one planning sprint with no subscription. Pro ($10/month or $80/year) keeps planning features on tap month to month or year to year — multi-country sweep, custom portfolio allocation, withdrawal strategies, PDF export, and more.
Anonymous session data is retained for 7 days. Signed-in user data is stored indefinitely and only accessible to you. We do not sell, share, or use your financial data for any purpose other than running your simulations.