How much do I need, and when can I stop working?

The portfolio at which withdrawing your chosen percentage each year covers your annual spending: spending divided by the withdrawal rate. At 4% that is 25 times your annual spending, so $60,000 a year needs $1,500,000. It says how much; the date on this page says how long it takes to get there.

It sets your FIRE number, which is yearly spending divided by your withdrawal rate. Then it grows what you have, plus what you add each month, at your return after inflation, and reports the first month the balance reaches that number. That month, counted from today, is your date. Two calculators can give different dates for the same person because of how they handle inflation, the withdrawal rate they use, the return they assume, and whether contributions rise with inflation.

The 4% rule comes from 30-year US market history (Bengen 1994; the Trinity study). It describes what worked in past US markets, not what will happen. A retirement that starts at 40 or 45 can last 50 years or more, so some planners use lower rates, often in the low-to-mid 3% range. A lower rate raises the number and pushes the date out: on $250,000 invested, $2,000 saved a month and $60,000 of spending, at a 7% return and 3% inflation, 3.5% instead of 4% moves 23.3 years to 25.8. The Monte Carlo simulator tests a rate against your own retirement length.

Because your FIRE number is in today’s dollars, so the balance has to be too. The real return is the return after inflation, (1 + return) ÷ (1 + inflation) − 1, so 7% with 3% inflation is 3.88%. Using the full 7% counts growth that inflation takes back: on $250,000 invested, $2,000 saved a month, $60,000 of spending and a 4% withdrawal rate, growing at the full 7% gives 16.6 years, and growing at 7% with 3% inflation taken out, as this calculator does, gives 23.3.

No. It treats your spending as after-tax, so the number is what you need to withdraw and spend. If most of your money is in pre-tax accounts, you have to withdraw more than you spend to pay the tax, so you need more than this number. The Roth conversion ladder and 72(t) calculators cover early access to those accounts.

It lowers the number, but by less than it looks. Enter the yearly amount and the age it starts, and the calculator makes the portfolio pay your full spending until then, and only what the income leaves uncovered after. For example, with $60,000 of spending, $30,000 a year starting at 67, a 4% withdrawal rate and a 3.88% real return (7% with 3% inflation), stopping at 45 needs $1,196,151: $750,000 for the $30,000 the income never covers, plus $446,151 to pay that $30,000 a year for the 22 years before it starts. Counting the income from day one would say $750,000, which leaves nothing for those 22 years; ignoring it says $1,500,000.

It can. Social Security retirement benefits cannot start before 62, and the benefit is based on your 35 highest years of earnings, with years of no earnings counted as zero, so stopping work early leaves zeros in the average. Claiming before your full retirement age also reduces the benefit for good: by 30% at 62 for anyone born in 1960 or later, whose full retirement age is 67. The Social Security break-even calculator (/tools/drawdown/social-security-break-even-calculator) estimates a benefit and compares claiming ages, so enter an estimate that reflects the years you will have worked.

Not on its own: put your expected health insurance cost inside your annual spending so the FIRE number covers it. If you would stop work before Medicare starts, that cost is yours until then. Medicare starts at 65 for most US citizens and long-term residents (immigrants on visas may not qualify), so budget for cover for as long as you would be outside it.

They are informal labels for how large the budget is, and there is no official definition. Lean FIRE means living on essentials only, so the number is smaller and arrives sooner. Regular FIRE funds a typical comfortable budget. Fat FIRE funds a generous one, with room for travel and extras, so the number is larger and takes longer. Dollar cut-offs differ from writer to writer, so this page uses your own spending; the Lean FIRE calculator splits essentials from discretionary spending to show the lean number and the years it saves.

It is an estimate, not a forecast. Markets do not return the same amount every year, and a bad run early in retirement can matter more than the average. The returns chart on this page shows how far the date moves when returns differ, and the Monte Carlo simulator tests how a portfolio of that size holds up across thousands of market paths once withdrawals start.