About FIRE Lab
FIRE Lab is a free retirement simulation lab. It exists because the statistical machinery behind serious retirement research — Monte Carlo simulation, multi-country historical data, dynamic withdrawal strategies — is usually locked inside academic papers or advisor software, while the free calculators that remain tend to hide their assumptions.
What it does
Every tool on this site runs on the same open engine: block bootstrap sampling over 150+ years of market history from 16 developed countries, so simulated futures preserve the multi-year crashes, recoveries, and inflation regimes that actually drive retirement outcomes. The methodology and data-sources pages document how everything works, including known limitations.
The simulators cover the full planning loop: accumulating toward a FIRE number, withdrawal-rate analysis, dynamic guardrail spending, asset allocation, and buy-versus-rent decisions.
Who builds it
FIRE Lab is built by Rens.AI as an independent project. It has no financial products to sell, takes no commissions, requires no account, and shows no ads.
What it is not
FIRE Lab is not financial advice. It is a statistical instrument: it shows how a plan would have fared across thousands of futures built from market history, which is not a prediction of your future. Simulation results should be one input into decisions you own — alongside professional advice where the stakes warrant it.