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FIRE by ageLean FIRE: how much you need
Lean FIRE is financial independence on a minimal budget, often $40,000 a year or less. At 4%, $30,000 a year takes $750,000; for a 50-year early retirement, Morningstar's 2.9% rate makes it $1,034,483.
Portfolio by spending
| Spending a year | 4% rule | 3.3% (40 years) | 2.9% (50 years) |
|---|---|---|---|
| $25,000 | $625,000 | $757,576 | $862,069 |
| $30,000 | $750,000 | $909,091 | $1,034,483 |
| $35,000 | $875,000 | $1,060,606 | $1,206,897 |
| $40,000 | $1,000,000 | $1,212,121 | $1,379,310 |
| $45,000 | $1,125,000 | $1,363,636 | $1,551,724 |
Why lean FIRE comes sooner
A low budget works twice: the target is smaller and more of your income can be saved. Earning $60,000 after tax and spending $30,000 means saving $30,000 a year; from nothing at 5% after inflation that reaches $750,000 in 16.6 years. Spending $45,000 on the same income saves $15,000 and takes 31.9 years.
What makes it fragile
- Little room to cut. A lean budget is mostly essentials, so flexible spending after a bad year is harder.
- Health insurance. Coverage before Medicare at 65 can take a large share of a small budget; see health insurance before Medicare.
- Big one-off costs. A roof, a car or a medical bill weigh more on $30,000 than on $80,000.
Lean FIRE by savings rate
On $50,000 of take-home pay, from nothing, at 5% a year after inflation and a 4% withdrawal rate:
| Spending a year | Savings rate | Saved a year | Years to lean FIRE |
|---|---|---|---|
| $25,000 | 50% | $25,000 | 16.6 |
| $30,000 | 40% | $20,000 | 21.6 |
| $35,000 | 30% | $15,000 | 28.0 |
Lean FIRE with a little income
A small side income makes a lean plan much sturdier. $10,000 a year of part-time pay lowers the $30,000 target from $750,000 to $500,000, and covers a bad year without selling. That is barista FIRE.
Questions people ask
What is lean FIRE?
Retiring early on a minimal, mostly essential budget. The portfolio needed is spending divided by the withdrawal rate, so $35,000 a year at 4% takes $875,000.
What is my lean FIRE number?
Your lean yearly budget divided by your withdrawal rate. The FIRE calculator shows lean, regular and fat numbers side by side, with the age you reach each.
How much is needed for lean FIRE?
For $25,000 a year, $625,000 at 4%; for $40,000, $1,000,000.
Related
Fat FIRE is the opposite end, and the five types of FIRE compares them.
Sources
- William P. Bengen, "Determining Withdrawal Rates Using Historical Data", Journal of Financial Planning, October 1994.
- Amy C. Arnott, "How Much Can You Safely Withdraw If You Retire Early?", Morningstar, September 15, 2026 (data as of September 30, 2025).
Keep reading
- Coast FIRE: how much you need by age
What coast FIRE means and the amount you need at 25, 30, 35, 40 and 45.
- Net worth by age in 2025: what the Fed's new survey shows
Median and average net worth by age from the Federal Reserve's 2025 survey, and what changed since 2022.
- How much do you need to retire at 40?
The portfolio you need by spending level for a 50-year retirement, what it takes to save it and how to bridge to 59½.
- What is FIRE? Financial independence in numbers
What financial independence means, the five versions and how much each one costs.
Last reviewed by Asier Fernández, editor, on . Educational information only, not financial advice. How we calculate