
The FI Calculator
An advanced FIRE calculator with powerful simulations
5 followers
An advanced FIRE calculator with powerful simulations
5 followers
Plan your path to Financial Independence. A free, private, and powerful tool to stress-test your retirement plan with historical data and Monte Carlo simulations. No ads, 100% private.








Hi everyone, I'm the creator of The FI Calculator. Thank you so much for checking out my project!
Like many of you on a FIRE journey, I was frustrated with the free tools out there. They felt either too simplistic for real-world planning or were cluttered with ads. I wanted to build the tool I always wished I had.
My goal was to make it powerful while being 100% free, ad-free, and completely private (all your financial data stays in your browser).
I've packed it with features designed to give you a truly comprehensive and realistic picture of your financial future:
๐ Advanced Simulations (The Core Engine): Don't just rely on simple averages. You can run your plan against every historical market cycle since 1928, or run thousands of random Monte Carlo futures to see the statistical probability of your plan's success.
โ๏ธ Interactive "What-If" Levers: This is my favorite feature for quick insights. You can use sliders to instantly see the impact of saving more, spending less in retirement, or adding a side income, without having to re-enter all your numbers.
๐ค Detailed Scenario Planning: Go beyond a single FIRE number. The calculator includes:
A "One More Year" analysis to quantify the powerful benefit of working just a little longer.
A "Coast FIRE" mode to find the point where you no longer need to save for retirement.
A detailed Event Timeline to model future expenses or income streams like college costs or an inheritance.
๐ Savings Comparison Plot: Visualize exactly how different savings rates can dramatically accelerate your journey to financial independence and impact your potential retirement income.
This has been a passion project, and for full transparency, the code is open-source with a non-commercial license. I'm here all day to answer any questions and would be incredibly grateful for your feedback!