Home › Lean FIRE Calculator
Lean FIRE Calculator
Enter a lean yearly budget and your current spending. You get the target for each and how many years the lean version saves.
| Level | Yearly spending | FIRE number | Time to reach it |
|---|---|---|---|
| Lean | $25,000 | $625,000 | 17 years 9 months |
| Current spending | $40,000 | $1,000,000 | 24 years 4 months |
| Fat (1.5 times current) | $60,000 | $1,500,000 | 30 years 9 months |
Example
Living on $25,000 a year needs $625,000, which takes 17 years 9 months from $50,000 when investing $1,500 a month. At $40,000 a year the target is $1,000,000 and takes 24 years 4 months.
How the lean fire calculator works
Lean FIRE is financial independence on a minimal budget. The number is calculated the same way as any FIRE number, as yearly spending divided by the withdrawal rate, using a lower spending figure.
Each level in the table uses the same investments and monthly contribution, so the difference in time comes only from the size of the target.
A lean budget leaves little room for surprises. Many people treat the Lean FIRE number as a milestone where work becomes optional in a pinch, and keep going towards a more comfortable figure.
Common questions
How much spending counts as lean?
There is no official line. In the United States the term often refers to budgets under about 40,000 a year for a household. What matters is that it covers your essentials where you live.
What is Fat FIRE?
The opposite end: financial independence with a generous budget. The table shows a level at 1.5 times your current spending for comparison.
What are the risks of Lean FIRE?
A small budget has few costs left to cut if markets fall or prices rise. Healthcare, housing repairs and family changes are the usual pressure points.