What is the 'Lean FIRE' movement, and how can it help you reach financial independence?

The Lean FIRE movement is a variation of the Financial Independence, Retire Early (FIRE) movement that focuses on living a more frugal lifestyle to achieve financial independence at an earlier age. Instead of aiming for a large retirement portfolio to support an expensive lifestyle, Lean FIRE followers keep their spending low so they require less money to retire.

This approach emphasizes drastically reducing current and future spending, which accelerates the retirement age. Lean FIRE followers estimate their annual expenses once they've reached financial independence and then determine their FIRE savings target. A common guideline is to multiply the annual spending by 25, based on the 4% rule of withdrawing 4% of their investment portfolio annually, adjusting for inflation.

To reach this goal sooner, Lean FIRE followers prioritize keeping expenses low, saving a significant portion of their income, and consistently investing those savings. However, Lean FIRE requires a more frugal lifestyle and may limit experiences during younger years. The strategy also depends on assumptions about inflation, investment returns, healthcare costs, and future spending needs, which can change significantly over time.

While Lean FIRE can be a good option for those comfortable with a scaled-down lifestyle, it's essential to consider potential future expenses like healthcare costs, housing, and growing family obligations. Balancing frugality with enjoying life and building flexibility into the plan is crucial, as early retirement could last 30 or 40 years or more.