How this Lean FIRE calculator works
Lean FIRE estimates the portfolio needed to retire on a lower annual spending level.
Lean FIRE Number = Lean Annual Expenses ÷ Withdrawal Rate
Best use case
- Minimalist retirement planning.
- Testing lower spending scenarios.
- Comparing Lean FIRE with regular FIRE or Fat FIRE.
Important note
Lean FIRE can be sensitive to healthcare, housing, taxes, and unexpected lifestyle changes.
How to use this calculator
- Enter realistic values that match your current situation.
- Press Calculate to refresh the estimate.
- Compare the main result with the supporting details in the result panel.
- Change one input at a time to see which variable affects the result most.
Planning note: Lean FIRE Calculator gives an educational estimate. It does not include every tax rule, fee, platform policy, market condition, or personal constraint, so use it as a quick planning reference rather than a final decision.