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.
Frequently Asked Questions
Is the 4% rule still valid for FIRE?
The 4% rule (Trinity Study) was based on a 30-year retirement. For FIRE retirees who may need 40-60 years of withdrawals, many financial planners recommend a more conservative 3-3.5% withdrawal rate. Our calculator lets you adjust the withdrawal rate to model different scenarios.
How do taxes factor into FIRE planning?
Taxes significantly impact FIRE calculations. Consider: (1) Roth conversion ladders for tax-free income, (2) long-term capital gains at 0% for income under ~$47,000, (3) Traditional IRA withdrawals taxed as income, (4) state taxes varying widely. Use our Roth Conversion Calculator to model tax-efficient withdrawal strategies.
What about health insurance for early retirees?
Before Medicare at 65, early retirees need private insurance. ACA marketplace plans with premium subsidies (available if income is under 400% of FPL) are the most common option. Managing taxable income to maximize subsidies is a key FIRE strategy — another reason Roth conversions matter.
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