About
This project exists to make the path to financial independence easier to understand. The goal is not to glamorize retiring early at any cost. It is to help people see the tradeoffs between spending, savings, investing, and time with enough clarity to make better decisions.
Who's Behind FI Plan Lab
FI Plan Lab was created by a software developer and personal finance enthusiast who believes financial independence planning should be accessible to everyone — not locked behind paywalls or buried in academic jargon.
The tools on this site are built with care using industry-standard financial formulas, peer-reviewed research (including the Trinity Study and safe withdrawal rate literature), and modern web technology. Every calculator runs entirely in your browser — your financial data never leaves your device.
Have questions, feedback, or ideas for new calculators? Use the contact form below — every message is read personally.
Mission
FIRE planning is often explained either too casually or too academically. This site sits in the middle. It uses real formulas, monthly compounding, and scenario analysis, but presents them in language that ordinary savers can use.
Methodology
The calculators on this site use deterministic compounding for accumulation and a Monte Carlo simulation for retirement stress testing. The most common sources behind the framework are the Trinity Study, safe withdrawal rate research, and long-run equity return assumptions used widely in the FIRE community.
For deeper reading, start with the 4% rule article and the guide to calculating your FIRE number.
Contact
Use this form for feedback, partnerships, or calculator questions.