Part 6/10:
A core concept within FIRE is the “FI number,” which represents the amount of savings needed to cover one’s living expenses indefinitely. The calculation involves multiplying annual expenses by 25. For example, if your annual expenses are $50,000, then your FI number is $1.25 million. Once this target is reached, one can withdraw a safe percentage annually—usually 4%—to sustain their lifestyle without employment.