Financial Independence, Retire Early (FIRE) is more than a trend — it's a math problem. Once you know the numbers, the path becomes clear.
What Is Your FIRE Number?
Your FIRE number is the amount of invested assets you need to cover your annual expenses indefinitely. The standard formula uses the 4% Rule: FIRE Number = Annual Expenses × 25.
If you spend $50,000/year: $50,000 × 25 = $1,250,000. Once you have $1.25 million invested, you can safely withdraw 4% per year ($50,000) and likely never run out of money.
The 4% Rule Explained
The Trinity Study (1998) found that withdrawing 4% annually from a portfolio of 50-75% stocks, adjusted for inflation, survived every 30-year period in history. Even the worst-case scenarios (retiring in 1929 or 1966) didn't deplete the portfolio.
Why Savings Rate Matters More Than Income
Here's the surprising math: your savings rate determines your time to FIRE more than your income does.
- 10% savings rate → ~51 years to FIRE
- 25% savings rate → ~32 years
- 50% savings rate → ~17 years
- 75% savings rate → ~7 years
Someone earning $60,000 and saving 50% ($30,000/year) reaches FIRE faster than someone earning $200,000 but saving only 10% ($20,000/year) — because the high saver also has lower expenses, meaning a smaller FIRE number.
Calculate Your Path
Use our FIRE calculator to find your number, track your progress, and see how many years until financial independence.