Frequently Asked Questions

What is Monte Carlo simulation?

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.

What countries and tax systems are supported?

Retirement Lab models income tax, capital gains tax, and wealth tax for 25+ countries, including the US, UK, Canada, Spain, Portugal, France, Germany, and more.

How accurate is the tax modeling?

Tax calculations use real bracket-based models with current published rates. They are simplified approximations — consult a qualified tax professional for your specific situation.

Is this financial advice?

No. Retirement Lab is a financial calculator. All results are hypothetical projections based on your inputs and assumptions.

What’s the difference between Free and Pro?

The full simulation engine is free for everyone. Pro ($10/month) adds planning features: multi-country sweep, dual-person modeling, custom portfolio allocation, withdrawal strategies, PDF export, and more.

How is my data stored? Is it private?

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.