FIRE number calculator

How much you need invested to live off your portfolio for good, from Lean FIRE to Fat FIRE, after any other income you expect.

Your FIRE number: $1.25M

That's 25 times the $50,000 a year your portfolio must cover, at a 4% withdrawal rate.

At 3.5%, for 40+ years: $1,428,571
At 4%, the classic rule: $1,250,000
At 4.5%, shorter retirements: $1,111,111

What would change your result

Expect Social Security? $24,000 a year of benefits would lower your number to $650,000.
A leaner plan on $38,000 a year needs $950,000.
Fat FIRE on $100,000 a year would need $2.5M.

What-ifs worked out from your own numbers. Not personal financial advice.

FIRE number

All amounts in today's dollars. Lean FIRE usually means under $40,000 a year; Fat FIRE, $100,000 or more.

Table by withdrawal rate

Withdrawal rate	FIRE number
3%	$1,666,667
3.25%	$1,538,462
3.5%	$1,428,571
3.75%	$1,333,333
4%	$1,250,000
4.25%	$1,176,471
4.5%	$1,111,111
4.75%	$1,052,632
5%	$1,000,000

How it's calculated

Your FIRE number is the portfolio whose withdrawals pay for the spending nothing else covers: (spending − other income) ÷ withdrawal rate.

At 4% that's 25 times the gap; at 3.5%, about 28.6 times. The chart shows how much a half-point on the withdrawal rate moves the target.

Other income should be in today's dollars and last for life, like Social Security or an inflation-adjusted pension. If it starts later than you retire, the years before it need extra savings: see the retire-at-60 guide for the bridge.

Questions people ask

What is a FIRE number?

The amount you need invested so that withdrawals at your chosen rate cover your yearly spending indefinitely. With the 4% rule it is 25 times your spending.

What is Lean FIRE?

Financial independence on a frugal budget, usually under $40,000 a year. It is reached sooner but leaves less room for surprises.

What is Fat FIRE?

Financial independence on a generous budget, usually $100,000 a year or more. The math is the same; the target is just much larger.

Should I include Social Security?

Yes, if you expect it. Enter your estimated yearly benefit from ssa.gov as other income. If it starts years after you retire, your savings also need to cover that gap.