The Lean FIRE Math
Lean FIRE targets annual spending of $25,000-$45,000 per household, requiring a portfolio of $625,000-$1,125,000 at a 4% withdrawal rate. The median U.S. household income of $80,610 (Census 2025), at a 41-45% savings rate after taxes, reaches a $750K target in approximately 14 years at 7% real returns. Savings rate — not income level — is the dominant variable.
What $30K/Year Looks Like
Housing ($900-1,200/month) is the controlling variable, requiring low-cost markets or a paid-off home. Food at $300-400/month (USDA Thrifty Plan baseline), healthcare at $200-500/month (ACA with subsidies managed via MAGI), transportation at $150-300/month (reliable used car owned outright), plus miscellaneous totals $21,000-$30,000/year.
Geographic Arbitrage
The most powerful Lean FIRE lever: international relocation to Portugal (45% below U.S. cost), Mexico (55% below), or Thailand (65% below) compresses portfolio requirements to $550K and timelines by 3-7 years. Domestically, moving from a median-cost city to Wichita or Huntsville reduces expenses 20-30%.
Risks and Mitigation
Healthcare is the existential risk (ACA premiums $4,200-$7,900/year before subsidies). Thin margins mean a 30% market drawdown pushes withdrawal rates from 4% to 5.7%. Mitigations: 2-3 year cash buffer, Guyton-Klinger guardrails (99%+ success rate over 40 years), and maintaining part-time income optionality.
Originally published on WealthWise OS Blog.