How the FIRE Calculator Works
The FIRE calculator uses three key inputs:
- Current savings — Your existing retirement portfolio
- Annual savings — How much you invest each year
- Annual expenses in retirement — Your target spending after FIRE
Using these, it calculates your FIRE number (annual expenses × 25) and projects how many years until your portfolio reaches that target, assuming a user-specified rate of return.
Savings Rate vs. Years to FIRE
Your savings rate is the single most important factor in reaching FIRE. Here's how savings rate affects your timeline (assuming 7% average return and starting from zero):
| Savings Rate | Years to FIRE | FIRE Type |
|---|---|---|
| 25% | ~32 years | Traditional |
| 35% | ~25 years | Traditional |
| 50% | ~17 years | Regular FIRE |
| 65% | ~10 years | Aggressive FIRE |
| 75% | ~7 years | Extreme FIRE |
Types of FIRE
- Lean FIRE — Minimalist living on under $40,000/year. Requires a smaller portfolio (~$1M or less) but means a frugal retirement.
- Regular FIRE — Middle-class lifestyle at $40,000-$100,000/year. Portfolio target: $1M-$2.5M.
- Fat FIRE — Comfortable/luxurious retirement at $100,000+/year. Portfolio target: $2.5M+.
- Barista FIRE — Partial retirement: your investments cover most expenses, but you work part-time for extras and health insurance.
- Coast FIRE — You've saved enough that, without adding another dollar, your portfolio will grow to support traditional retirement by age 65. You only need to cover current living expenses.
Related Calculators & Guides
- Roth Conversion Calculator — Tax-efficient FIRE withdrawal strategy
- FIRE Retirement Calculator Complete Guide
- 4% Safe Withdrawal Rate Explained
- How Inflation Erodes Your Nest Egg
- All Retirement Calculators