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FIRE Calculators

Lean FIRE Calculator

Lean FIRE target for a frugal retirement on a lower budget (typically under $40k/year), with time to reach it.

Enter values

Results update as you type.

Result

FIRE number

$700,000.00

Years to reach it

10 years

Gap today
$550,000.00
Progress
21.43%

Uses a constant real return; markets fluctuate. Not financial advice.

About the Lean FIRE Calculator

Lean FIRE target for a frugal retirement on a lower budget (typically under $40k/year), with time to reach it.

Also known as: lean fi, frugal fire.

How to use this calculator

  1. Enter annual spending in retirement, safe withdrawal rate, current investments, annual savings and the other fields.
  2. The result updates instantly as you type — press Calculate (or Enter) at any time.
  3. Review the breakdown shown under the main result.
  4. Use Copy result or Share to save the answer or send a link with your inputs.

Formula

FIRE number = annual spending ÷ withdrawal rate (≈ 25× spending at 4%)

Worked example

Using the values pre-filled in the calculator above:

  • Annual spending in retirement = 28,000
  • Safe withdrawal rate = 4 %
  • Current investments = 150,000
  • Annual savings = 40,000
  • Real (after-inflation) return = 5 %

the calculator returns:

  • FIRE number: 700,000
  • Years to reach it: 10 years
  • Gap today: 550,000
  • Progress: 21.43%