What Is a FIRE Number Calculator?
A FIRE (Financial Independence, Retire Early) number calculator determines the total investment portfolio size you need to sustain your lifestyle without employment income. Once your investments reach this target, the passive income they generate can cover your annual living expenses indefinitely.
How to Use This FIRE Number Calculator
- Enter your estimated annual living expenses in retirement.
- Set your expected safe withdrawal rate (the default is 4%).
- Click “Calculate” to see your FIRE number—the portfolio target needed for financial independence.
Key Concepts
The FIRE number is derived from your annual expenses divided by your safe withdrawal rate (SWR). At a 4% SWR, the formula is simply Annual Expenses × 25. The 4% rule originates from the Trinity Study, which found that a diversified portfolio surviving 30 years of withdrawals at 4% had a high historical success rate. Variations include Lean FIRE (minimal spending), Fat FIRE (comfortable spending), and Barista FIRE (partial employment supplementing investments).
Frequently Asked Questions
What is the 4% rule?
The 4% rule suggests withdrawing 4% of your portfolio in the first year of retirement, then adjusting for inflation annually. Historical data shows this approach sustains a 30-year retirement with high probability.
Is a 4% withdrawal rate safe for early retirees?
Because early retirees may need their portfolio to last 40–60 years, a more conservative 3–3.5% rate is often recommended. This increases the FIRE number but adds a larger safety margin.
How do I reduce my FIRE number?
Lower your annual expenses. Every $1,000 reduction in annual spending decreases your FIRE number by $25,000 (at a 4% SWR). Relocating to a lower cost-of-living area or eliminating debt are effective strategies.