What is my Lean FIRE number?

Financial independence on a bare-bones budget: your essentials only, with little or no room for extras. The number is yearly essentials divided by your withdrawal rate. There is no official definition, and what counts as lean depends on where you live and how many people you support, so this page uses the essentials you enter.

Add up what you would have to pay in a lean year: housing, food, utilities, insurance, transport and healthcare, including health insurance until Medicare or other cover starts. Leave out costs that will have ended by the time you stop, such as a loan you will have paid off or childcare; a cost that runs on into retirement still has to be funded until it ends. A $500 monthly payment that ends before you stop but is left in essentials adds $150,000 to the number at a 4% withdrawal rate.

It varies a lot by household. The starting split here is 75% essentials to 25% discretionary, which is the share of average US household spending that went to housing, food at home, transportation and healthcare in the BLS 2024 Consumer Expenditure Survey (leaving out the Social Security and retirement-plan deductions taken from pay). It is a starting point, not your number, so replace it with your own essentials. Discretionary spending is everything you could cut in a bad year: travel, dining out, hobbies and gifts.

It depends on your split and your savings. At a 7% return, 3% inflation and a 4% withdrawal rate, on $250,000 invested, $2,000 saved a month and a $60,000 budget of which $45,000 is essential, the lean number of $1,125,000 is reached in 18.2 years rather than 23.3 for the full $1,500,000: 5.1 years sooner.

A smaller number arrives sooner, but there is no discretionary spending left to trim if markets fall or costs rise, and health insurance before Medicare can be a large essential. Medicare starts at 65 for most US citizens and long-term residents (immigrants on visas may not qualify), so some people need cover for longer. One way to use the lean number is as a floor to fall back on if the plan hits a bad decade.

Lean FIRE shrinks the target by cutting the budget. Coast FIRE means you already have enough invested that, left to grow, it reaches your number by a normal retirement age, so you can stop saving. Barista FIRE means part-time income covers some of your spending for a while, so the portfolio only has to fund the gap until that work stops, and it must still grow to the full FIRE number by then.