How much is enough? The multiple logic

#The number is born from your spending

The FIRE target is not a vague "big number." It is a concrete number derived from your spending.

The logic is simple: the machine has to produce your outgoing every year. So the required capital is a multiple of your annual expense.

#Where does the multiple come from?

The multiple is the inverse of the question "what percentage of your capital do you withdraw each year":

• If you plan to withdraw 4% of your capital per year, the required capital is 25 times your annual expense (because 100 / 4 = 25).
• If you are more cautious and withdraw 3%, the multiple rises to 33 (100 / 3).

So a low withdrawal rate = a high multiple = a bigger target = safer. A high withdrawal rate = a low multiple = a smaller target = riskier.

#Two levers that shrink your number

If the target number looks scary, remember two levers:

Note: cutting your spending brings the target closer from two directions — it shrinks the required capital AND grows your saving. That is why in the FIRE community the savings rate is discussed even more than returns.

#A real-frame warning

Once more the lesson of the awakening idea: think of this number in real terms. The number you compute with today's expense must cover an expense that has grown with inflation years later. A nominal target shrinks fast under high inflation. The next section addresses exactly this.