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Lean FIRE

Lean FIRE is early retirement on a deliberately frugal budget — a smaller number, reached sooner.

What Lean FIRE means

Lean FIRE targets a modest annual budget — often under about $40,000, roughly 0.7× a typical FIRE budget. The math is the same as any FIRE number (annual expenses ÷ safe withdrawal rate); the difference is a lower spending target, which means a smaller portfolio and an earlier finish line.

The trade-off

A lean budget gets you out sooner, but leaves less margin for surprises — healthcare, family changes, or higher-than-expected inflation. Many lean retirees keep some flexible income or a cash buffer. The calculator lets you test a lower spending figure and see exactly how many years it shaves off.

FIRE calculator

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This calculator gives educational estimates only. It plans in today's dollars using a real (after-inflation) return, so your FIRE number reflects total spending including any taxes you'll owe. Projections are illustrative, not guarantees, and this is not financial advice.

Questions

How much is Lean FIRE?

There's no fixed line, but Lean FIRE typically means an annual budget under roughly $40,000, or about 0.7× a standard FIRE budget. Your Lean FIRE number is that budget divided by your safe withdrawal rate.

Is Lean FIRE risky?

It has less margin than a standard budget, so it's more exposed to unexpected costs and inflation. Many lean retirees keep part-time income or a larger cash buffer to compensate.

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