Calculator
FIRE Number Calculator
Your FIRE number is the portfolio size that lets you live off investment returns indefinitely. Enter your numbers below — results update as you type.
Your numbers
How much you spend per year
$
4.0%
4% is the standard; use 3–3.5% for 40+ year retirement
2% (conservative) 6% (aggressive)
For timeline calculation
Your total invested assets today
$
How much you invest per year
$
7.0%
Inflation-adjusted annual return (7% = historical average)
3% 12%
Your FIRE Number
$1,250,000
Progress to FIRE 8%
$100k saved $1.25M needed
Time to FIRE
—
years away
—
projected year
How it works
The math behind this calculator
1
Enter your annual expenses
Type in how much you spend per year — or estimate based on your monthly spending multiplied by 12. This is the single most important number.
2
Set your safe withdrawal rate
The default is 4%, based on the Trinity Study. Use 3–3.5% if you plan a very long retirement (40+ years). Adjust the slider to see how it changes your number.
3
Add your current savings
Enter your current invested assets — retirement accounts, brokerage accounts, etc. This shows your progress and reduces the gap.
4
Enter your annual contribution
How much do you invest per year? This determines how quickly you close the gap to your FIRE number.
5
Read your results
Your FIRE number, progress percentage, and estimated years to financial independence update instantly as you type.
FIRE Number formula
FIRE Number = Annual Expenses ÷ SWR e.g. $50,000 ÷ 0.04 = $1,250,000
Years to FIRE formula
n = log((FV + PMT/r) / (PV + PMT/r)) / log(1+r) FV = FIRE number · PMT = annual savings · PV = current savings
Frequently asked questions
What is a FIRE number?
Your FIRE number is the total investment portfolio value you need to retire. It is calculated by dividing your annual expenses by your safe withdrawal rate. At the standard 4% rule, this equals 25 times your annual spending.
What is the 4% rule?
The 4% rule comes from the 1994 Trinity Study. It found that a diversified portfolio can sustain a 4% annual withdrawal for at least 30 years in nearly all historical market scenarios, including the Great Depression and 1970s stagflation.
Should I use a lower withdrawal rate for early retirement?
Yes, if you plan to retire for 40–50 years, many financial planners recommend a 3–3.5% withdrawal rate to account for the longer time horizon. Use the slider in the calculator to explore how a lower rate affects your FIRE number.
What investment return should I assume?
Most FIRE planners use 7% as the expected real (inflation-adjusted) annual return, based on the long-term historical average of diversified US stock market index funds. This is already net of inflation, so your FIRE number does not need to be adjusted for inflation separately.
Does the calculator include inflation?
Yes, implicitly. The default 7% expected return is a real return — already adjusted for inflation. Your expenses and FIRE number are in today's dollars. If you enter a nominal return (e.g. 10%), the timeline will be optimistic; adjust down by ~3% to approximate inflation.