About the FIRE Number Calculator
What is the FIRE Number Calculator?
Your FIRE number is the size of the investment portfolio that can pay your living expenses forever through safe withdrawals. It is the finish line for anyone pursuing financial independence.
Enter your annual expenses, the withdrawal rate you are comfortable with, inflation and the years until you want to retire. The calculator shows the FIRE number today, the inflated number at your retirement date and lean (70%) and fat (150%) versions.
How to use the FIRE Number Calculator
- Current Annual Expenses (₹) (sample: 12,00,000)
- Safe Withdrawal Rate (%) (sample: 4)
- Inflation (% per year) (sample: 6)
- Years Until You Want to Retire (sample: 15)
- Press Calculate FIRE Number (results also refresh as you type). The result card shows the Your FIRE Number (Today), along with FIRE number at your retirement date, Expense multiple, Annual expenses at retirement and Lean FIRE (70% of expenses).
Formula used
FIRE number = Annual expenses ÷ Safe withdrawal rate
- At retirement = FIRE number × (1 + inflation)^years
- Multiple = 100 ÷ withdrawal rate (25× at 4%, 33× at 3%)
Lean FIRE assumes a frugal 70% of current spending; fat FIRE a comfortable 150%.
Worked example
These are the sample values already filled in the calculator above, and the result it returns for them:
| Input | Sample value |
|---|---|
| Current Annual Expenses (₹) | 12,00,000 |
| Safe Withdrawal Rate (%) | 4 |
| Inflation (% per year) | 6 |
| Years Until You Want to Retire | 15 |
| Result | Value |
|---|---|
| Your FIRE Number (Today) | ₹3,00,00,000 |
| FIRE number at your retirement date | ₹7,18,96,746 |
| Expense multiple | 25× |
| Annual expenses at retirement | ₹28,75,870 |
| Lean FIRE (70% of expenses) | ₹2,10,00,000 |
| Fat FIRE (150% of expenses) | ₹4,50,00,000 |
Tips for using the FIRE Number Calculator
- Exclude costs that will end before retirement, such as a home loan that will be paid off.
- Add a separate buffer for large one-off costs like children's education.
- Recalculate every year as your lifestyle changes.