Lean FIRE Calculator
Find your Lean FIRE number: the portfolio you need to retire early on a minimal, tightly-budgeted lifestyle — the fastest route to financial independence.
This projection assumes a steady, unchanging return. Curious how your plan holds up against real market volatility? Try the Monte Carlo calculator →
How the Lean FIRE number is calculated
Divide your annual living expenses by your safe withdrawal rate (typically 4%, i.e. 25x expenses). Because Lean FIRE budgets are smaller to begin with, this number is reachable much faster than a standard or Fat FIRE target — the tradeoff is less room for lifestyle inflation later. The default return assumes historical U.S. stock market averages; see our methodology pagefor the full explanation and how to customize it.
FAQ
What counts as Lean FIRE?
There's no official cutoff, but Lean FIRE generally means retiring on a notably minimal, tightly-budgeted lifestyle — often cited as under roughly $25,000-$40,000 a year for a single person, adjusted for your area's cost of living. It gets you to financial independence with a smaller portfolio, faster, in exchange for a leaner budget.
Is Lean FIRE risky?
A thinner expense margin means less room to absorb surprise costs (medical bills, home repairs, inflation). Many Lean FIRE retirees build in flexibility — a willingness to pick up part-time work, a larger emergency fund, or a slightly lower withdrawal rate than the standard 4% — to offset that risk.
Lean FIRE vs Fat FIRE — what's the difference?
They're the same formula (annual expenses ÷ withdrawal rate) applied to very different lifestyles. Lean FIRE targets minimal, essentials-only spending to reach independence as early as possible. Fat FIRE targets an upscale, no-compromise lifestyle, which requires a much larger portfolio.