How to Calculate Fat FIRE
What is Fat FIRE?
Fat FIRE is financial independence with a generous lifestyle budget, typically $80,000–$150,000+ per year. It requires a larger portfolio but allows maintaining or improving your pre-retirement standard of living.
Formula
portfolio_needed = annual_expenses / withdrawal_rate (same as Lean FIRE, different expense level)
- expenses
- Annual expenses ($) — Annual spending (higher than Lean FIRE)
- wr
- Withdrawal rate (%) — Safe withdrawal rate (3–4%)
- portfolio
- Portfolio ($) — Total needed to support high-expense lifestyle
Step-by-Step Guide
- 1FIRE Number = Annual Expenses × 25 (4% rule)
- 2Fat FIRE typically targets $80K+ annual spending
- 3Conservative investors may use 3–3.5% withdrawal rate (× 28–33)
- 4Healthcare costs pre-Medicare are a key Fat FIRE consideration
Worked Examples
Input
$100,000/year lifestyle
Result
FIRE number $2,500,000
Input
$150,000/year
Result
FIRE number $3,750,000
Input
$80,000/year at 3.5% rate
Result
Portfolio needed $2,285,714
Frequently Asked Questions
What is Fat FIRE?
Retiring with enough to support a comfortable, high-expense lifestyle ($60K–150K+/year). More cushion and flexibility than Lean FIRE.
How much portfolio do I need for Fat FIRE?
Divide annual expenses by withdrawal rate. Example: $100K/year ÷ 0.04 = $2.5M portfolio.
What about required minimum distributions (RMDs)?
Traditional IRAs require RMDs at age 73 (2023 rules, may change). Plan for tax implications.
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