Lean FIRE, Fat FIRE and Barista FIRE: What Each Means in Numbers

The FIRE label you choose is really a spending decision. Here is what each style costs in invested money and in years.

Last updated: October 12, 2026. Figures were calculated with this site's FIRE calculator code on that date, using the stated inputs.

The number depends on spending, not income

Financial independence needs a portfolio large enough to fund your spending indefinitely. The FI number is yearly spending divided by the withdrawal rate. Income only matters because it determines how fast you can save. Because the target is built from spending, the same person can reach very different goals by choosing very different lifestyles.

Yearly spending	At 3.25%	At 3.5%	At 4%
$25,000	$769,231	$714,286	$625,000
$40,000	$1,230,769	$1,142,857	$1,000,000
$60,000	$1,846,154	$1,714,286	$1,500,000
$100,000	$3,076,923	$2,857,143	$2,500,000

Every $1,000 of yearly spending you can avoid removes $25,000 from the target at 4%, or about $31,000 at 3.25%.

Lean, regular and fat compared

Take a 35-year-old with $100,000 invested who earns $100,000 after tax and saves 30% ($30,000 a year). Assume 7% growth, 3% inflation and a 4% withdrawal rate. Only the target retirement budget changes:

Style	Retirement spending	FI number	Years to FI	Age
Lean	$30,000	$750,000	15	50
Regular	$50,000	$1,250,000	23	58
Fat	$90,000	$2,250,000	33	68

The same saving habit reaches the lean goal 18 years sooner than the fat one. Lean FIRE means committing to a modest, disciplined budget, often with low housing costs, and it can leave little room for emergencies or inflation in a category such as healthcare. Fat FIRE means a comfortable lifestyle but a longer wait, which is a different risk: you may be working at 68 for a goal that could have been met at 58 with a smaller spending plan.

Barista FIRE

Barista FIRE is a middle path: you stop full-time work, but earn part-time income that covers part of your spending. If your budget is $50,000 and part-time work covers $20,000, the portfolio only needs to support $30,000, which is the lean figure of $750,000 at 4%. In the example above that moves the date from age 58 to age 50.

That earlier date has costs worth naming. The plan depends on being able to keep earning, and health insurance is the item most often cited as a reason people stay in full-time jobs. Part-time income also continues to need to cover inflation. The CFPB's retirement guidance reminds readers that retirement can last 20 years or more, and an early start can mean decades more than that. A barista plan is safest as a bridge: part-time income in the early years, then a portfolio that has had time to grow before you start drawing on it fully.

Choosing a style

Start from the budget you actually have. If you currently spend $42,000, a $30,000 lean plan is a 29% cut, a real change in how you live.
Pick the withdrawal rate deliberately. A longer retirement usually calls for a lower rate, which raises every number in the first table. Use the withdrawal simulator to see the difference between 4% and 3.5% over 40 years.
Build in flexibility. A lean plan that can flex up by $5,000 in a hard year is much safer than one that cannot.
Revisit it. Move through the stages as your circumstances change: lean when you stop, barista in the early years, regular when the portfolio has grown.

Run your own numbers in the FIRE calculator by filling in the optional "spending in retirement" field, and compare what savings rate each style needs in the savings rate scenarios.

Methodology and sources

FI number = yearly spending / withdrawal rate. The timeline rows use the project function in this site's logic file with the age, savings, income, savings rate, return, inflation and withdrawal rate stated above, and the retirement spending set by the style. The barista example assumes the part-time income covers the stated amount for the whole period, which is an assumption, not a certainty.

Sources

Retirement Researcher: Safe Withdrawal Rates for Retirement and the Trinity Study: the 4% guideline and why lower rates are used for longer retirements.
Consumer Financial Protection Bureau: Retirement: retirement can last 20 years or more.

Limitations

Return, inflation, spending and income are constant in every example.
Taxes, healthcare and the cost of part-time work are not modelled.
The named styles have no formal definition; the dollar amounts here are examples.

Not financial advice. This page is general education from an independent website. It is not personal financial, tax, legal or insurance advice and not a recommendation to buy, sell or take out any product. Consider speaking with a qualified professional before making decisions.