Find out exactly how much you need to retire early. Adjust your inputs and see your number update instantly.
What is a FIRE Number?
Your FIRE number is the total amount of money you need invested so that your portfolio's returns can cover your living expenses indefinitely — without ever running out. Once you hit it, work becomes optional.
The concept comes from the FIRE movement (Financial Independence, Retire Early), which has grown significantly over the past decade, particularly among millennials and Gen Z who want to escape the traditional 40-year career track.
How to Calculate Your FIRE Number
The classic formula is based on the 4% Rule, which comes from the 1998 Trinity Study. It found that withdrawing 4% of your portfolio annually — adjusted for inflation — has historically lasted 30+ years across almost all market conditions.
FIRE Number = Annual Expenses ÷ Safe Withdrawal Rate
Example: $40,000 ÷ 0.04 = $1,000,000
If you spend $40,000 a year and use a 4% withdrawal rate, your FIRE number is $1,000,000. Spend $60,000 a year? You need $1,500,000. The formula scales directly with your lifestyle.
The 4% Rule — Is It Still Valid?
The 4% rule was designed for a 30-year retirement horizon. If you're retiring at 35 instead of 65, you may be drawing down for 50+ years, which warrants a more conservative withdrawal rate of 3–3.5%. That's why our calculator lets you adjust the safe withdrawal rate — try 3.5% to see how your number changes.
Types of FIRE
- Lean FIRE — Living frugally on $25,000–$40,000/year. Smaller number but a minimalist lifestyle.
- Fat FIRE — Retiring comfortably on $80,000–$120,000+/year. Larger portfolio, no lifestyle sacrifice.
- Barista FIRE — Quitting your main career but working part-time to cover some expenses.
- Coast FIRE — Saving enough early so investments grow to your FIRE number on their own.
How to Reach FIRE Faster
- Increase your savings rate — even an extra $500/month compounds significantly over 15 years.
- Reduce retirement expenses — spending $5,000 less per year cuts your FIRE number by $125,000 at a 4% SWR.
- Maximize tax-advantaged accounts — 401(k), Roth IRA, and HSA contributions grow faster than taxable accounts.
- Invest consistently — time in the market beats timing the market. Diversified index funds historically return ~7% annually after inflation.
Frequently Asked Questions
What is a good FIRE number?
There's no universal answer — it depends entirely on your annual expenses. A lean lifestyle spending $30,000/year requires $750,000 at a 4% withdrawal rate. A comfortable lifestyle at $80,000/year needs $2,000,000. The best FIRE number is the one that funds your specific life.
Is the 4% rule safe for early retirement?
The 4% rule was tested for 30-year retirements. For 40–50 year retirements (retiring in your 30s or 40s), many financial planners recommend using 3%–3.5% to be safer. Try adjusting the withdrawal rate slider to see how it changes your number.
Should I include Social Security in my FIRE calculations?
If you're planning to retire before 62, Social Security is likely decades away and uncertain. Most FIRE planners recommend calculating your number without it, then treating any Social Security income as a buffer. If retiring closer to 60, you might factor in a conservative estimate.
Does the FIRE number account for inflation?
Yes — the 4% rule inherently accounts for inflation because you increase your withdrawal amount each year with inflation. This calculator uses a real (inflation-adjusted) return rate, which is your expected return minus the inflation rate you enter.
What counts toward my current savings?
Include all invested assets: 401(k), IRA, Roth IRA, brokerage accounts, and other investment accounts. Don't include your emergency fund or home equity (unless you plan to sell your home in retirement).
How accurate is this calculator?
This calculator uses standard compound interest formulas with inflation-adjusted returns. It's a planning tool, not a guarantee — real returns vary year to year. Run multiple scenarios using different return rates to stress-test your plan.