About fyrslf

fyrslf started with a simple itch: wanting an easy but genuinely powerful way to model my own financial future. The calculators I could find were either too simplistic to trust or too clunky to actually use, so I decided to build the tool I wished existed.

The result is a FIRE — financial independence, retire early — calculator that lets you sketch out a real plan in minutes: current savings across account types, contributions, expected returns, inflation, Social Security and pensions, one-off windfalls, and how long it all needs to last. You can see your projection update as you go, compare scenarios side by side, and share a plan with a partner.

Once it was useful to me, sharing it with anyone else who might find it useful was the obvious next step. fyrslf is free to use, and there are no paid tiers planned.

How it works

fyrslf runs almost entirely in your browser. Your inputs are saved locally so you can pick up where you left off, and if you sign in, your saved scenarios sync so you can reach them from anywhere. Everything the tool produces is an estimate based on the assumptions you provide — a starting point for thinking, not a guarantee.

Get in touch

Questions, ideas, or bug reports are always welcome at support@f0x.cc.