What counts as Lean FIRE?

There is no official line. Many sources describe it as living on a modest budget, and this tool uses about 25,000 US dollars a year as its guide. A single person in a low-cost area and a family in an expensive city will draw the line differently.

Is the 4% rule safe for a long lean retirement?

The 4% rule comes from historical studies of 30-year retirements. Early retirees face a longer horizon, so many people test lower rates such as 3.5% in this calculator to see the effect.

How can I reach Lean FIRE faster?

Lowering expenses helps twice: it raises the amount you can save each month and it shrinks the target. Try reducing annual expenses by 10% and compare the years to FIRE.

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Lean FIRE Calculator

Lean FIRE means retiring early on a deliberately small budget. Because your spending is low, your FIRE number is low too, so you can often get there years sooner than a typical plan. This calculator starts from a lean budget and shows what it takes.

Currency

Current Age

Current Portfolio

Monthly Contribution

Annual Expenses in FIRE

Expected Real Return

Safe Withdrawal Rate

Effective Tax Rate

FIRE Number

$735,294 dollars

FIRE Age

50.3

Years to FIRE

20.3 yrs

Monthly spending in retirement: $2,083 dollars

Your spending range: Lean

How it works

Your FIRE number scales directly with spending: every extra 1,000 of annual expenses adds about 25,000 to the target at a 4% withdrawal rate. Lean FIRE works by keeping the expense side small through housing, transport and lifestyle choices.

This tool treats annual spending of roughly 25,000 US dollars or less as a lean budget, and scales that line for other currencies. Definitions vary by country and household size, so use the label as a guide, not a rule.

The formula

FIRE number = annual expenses ÷ (1 − tax rate) ÷ withdrawal rate.

Who it suits

It suits people who are happy with a simple lifestyle, can live in a lower-cost place, or have a partner or household that shares costs.

What to watch out for

A small budget leaves less room for surprises such as medical bills, home repairs, or inflation in your own spending. Many lean retirees keep a cash buffer or a flexible part-time option.

Frequently asked questions

What counts as Lean FIRE?: There is no official line. Many sources describe it as living on a modest budget, and this tool uses about 25,000 US dollars a year as its guide. A single person in a low-cost area and a family in an expensive city will draw the line differently.
Is the 4% rule safe for a long lean retirement?: The 4% rule comes from historical studies of 30-year retirements. Early retirees face a longer horizon, so many people test lower rates such as 3.5% in this calculator to see the effect.
How can I reach Lean FIRE faster?: Lowering expenses helps twice: it raises the amount you can save each month and it shrinks the target. Try reducing annual expenses by 10% and compare the years to FIRE.

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