Understanding the FIRE Movement and the 4% Rule
FIRE stands for Financial Independence, Retire Early. The idea is simple. You save and invest a large share of your income while you work, and once your investments can cover your living costs forever, work becomes optional. Some people stop working entirely. Others switch to part time jobs, passion projects, or slower careers. The common thread is that money stops making the decisions.
What Is a FIRE Number?
Your FIRE number is the portfolio size that lets you live off your investments. The classic shortcut is to multiply your annual spending by 25. If you spend $40,000 a year, your FIRE number is $1,000,000. This comes from the 4% rule, a guideline based on historical research into how much a retiree could withdraw each year from a diversified portfolio without running out of money over a 30 year retirement.
How the 4% Rule Works
The rule says you withdraw 4% of your portfolio in the first year of retirement, then adjust that amount for inflation every year after. In the research behind it, a portfolio of stocks and bonds survived this withdrawal pattern in the vast majority of historical periods. It is a planning guideline rather than a guarantee, which is why many early retirees aim for a little extra cushion or stay flexible with spending in bad market years.
Why Your Savings Rate Matters More Than Returns
The fastest lever in the calculator above is not the return slider. It is the gap between what you earn and what you spend. A higher savings rate works twice: you invest more each month, and you prove you can live on less, which shrinks the FIRE number itself. That is why someone saving half their income can often reach independence in around 15 to 17 years, starting from zero.
Play with the sliders, then explore our guides below to go deeper into savings rates, index investing, and withdrawal strategies. Everything here is educational. For decisions about your own money, talk to a qualified financial adviser.
