Lean FIRE Calculator
Retire early on a frugal lifestyle. Lean FIRE means achieving financial independence on a minimal budget — reaching your number faster by keeping costs low.
Your Details
Lean FIRE Number
£571,429
At 3.5% withdrawal
Years to FIRE
23 yrs
FIRE age: 53
Coast FIRE Number
£53,522
Invested today to coast
Annual Contribution
£10,000
Needed to hit target
Portfolio Projection
Assumes 7% nominal annual return. Not inflation-adjusted.
What is Lean FIRE?
Lean FIRE is financial independence achieved on a tight budget — typically under £20,000–£25,000 per year in the UK. Because your target income is low, your FIRE number is smaller and reachable much sooner than standard FIRE. The tradeoff is a frugal lifestyle with little discretionary spending.
Lean FIRE practitioners often use a slightly more conservative safe withdrawal rate (3.5%) to provide extra buffer against sequence-of-returns risk over a longer retirement period.
Lean FIRE strategies to reach your number faster
Minimise housing costs
Rent a room, house hack, or move to a lower cost-of-living area to drastically cut your biggest expense.
Cut lifestyle inflation
Avoid upgrading your lifestyle as your income rises. Save every raise instead.
Optimise your tax
Maximise ISA and pension contributions. Tax-free growth is the most powerful tool in the UK.
Geographic arbitrage
Retire in a lower cost country where your Lean FIRE income goes much further.