Interactive financial calculator
FIRE Number Calculator
A FIRE number is an illustrative portfolio target based on annual expenses and a chosen withdrawal rate.
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Methodology & Assumptions
How this estimate is calculated
Formula: Annual Expenses ÷ Withdrawal Rate. Informed by Cooley, Hubbard, and Walz's historical withdrawal-rate research. The 4% default is an illustrative rule for a 30-year horizon, not a guarantee. The return input is treated as real (after inflation).
Illustrative result: figures are rounded for display after calculations use full numeric precision. Actual results may differ.
Currency: dollar symbols are a display convention. Enter every monetary amount in one consistent currency; the calculator does not convert currencies or apply jurisdiction-specific tax rules.
What Is a FIRE Number?
A FIRE number is an estimated invested portfolio target intended to support withdrawals for living expenses. The term comes from the FIRE movement: Financial Independence, Retire Early. Actual sustainability depends on returns, inflation, fees, taxes, spending flexibility, and the retirement horizon.
The most widely used formula is the 25x rule, derived directly from the 4% safe withdrawal rate:
FIRE Number = Annual Expenses × 25
If you spend $50,000/year, the 25x rule produces a $1,250,000 illustrative target. Four percent of that starting portfolio equals $50,000 in year one; it does not ensure returns will cover every future withdrawal.
FIRE Numbers by Annual Spending
| Annual Spending | 4% Rule (25x) | 3.5% Rule (28.6x) | 3% Rule (33x) |
|---|---|---|---|
| $30,000 | $750,000 | $857,000 | $990,000 |
| $50,000 | $1,250,000 | $1,429,000 | $1,650,000 |
| $60,000 | $1,500,000 | $1,714,000 | $1,980,000 |
| $80,000 | $2,000,000 | $2,286,000 | $2,640,000 |
| $100,000 | $2,500,000 | $2,857,000 | $3,300,000 |
Use a 3.5% withdrawal rate (28.6x multiplier) if you plan to retire in your 40s with a 35-40 year horizon. Use 3% (33x) for a 40-50 year retirement horizon and maximum safety.
How to Use This Calculator
Enter your annual expenses and adjust the withdrawal rate slider to match your retirement timeline. The calculator instantly shows your FIRE number, current gap, and estimated time to reach financial independence based on your current savings and monthly contributions.
If you choose to copy a scenario link, the selected inputs are included in the URL. Use the separate clean share action when you do not want to include financial values.
Two Levers That Move Your FIRE Number
Reduce expenses. Every $100/month cut from spending reduces your FIRE number by $30,000 at the 4% withdrawal rate. Lower spending simultaneously reduces the target and increases monthly savings — the most powerful lever available.
Adjust withdrawal rate. Dropping from 4% to 3.5% increases the target by about 14%. A lower initial withdrawal may provide more room for uncertainty, but this calculator does not model portfolio survival.
Related: Calculate your Coast FIRE number — the amount needed to stop saving and let compound growth carry you to retirement.
Frequently Asked Questions
Is the 4% rule still useful?
It remains a commonly discussed historical planning framework, not a forecast. Outcomes depend on retirement length, asset allocation, fees, taxes, market sequence, and spending flexibility. Test other rates and review the limitations before using it as one input to a plan.
Should I include home equity in my FIRE number?
No — count only liquid, investable assets. Your primary residence is not a retirement income source unless you sell and downsize. Home equity is worth tracking in your net worth, but your FIRE number should reflect only portfolio assets that generate returns.
What if I have Social Security or a pension?
Income that begins at retirement can reduce the expenses a portfolio must cover. If it begins later, model the intervening years separately instead of subtracting it from every retirement year. Eligibility, tax treatment, and start dates vary by program and country.
How does inflation affect my FIRE number?
The 4% rule already accounts for inflation — it assumes you increase withdrawals by the inflation rate each year. Calculate your FIRE number using today's dollars; the withdrawal mechanism handles future inflation automatically. Use our inflation calculator to see how inflation erodes purchasing power over time.
Can I retire before reaching my full FIRE number?
Yes — with supplemental income. Many people retire at 90-95% of their FIRE number while maintaining small side income (consulting, part-time work, rental income) that covers the gap. This hybrid approach, sometimes called Barista FIRE or semi-retirement, is very common in practice.