The Types of FIRE Explained

One formula, different inputs

The FIRE labels sound like competing philosophies. They are not. Every one of them is built on the same calculation — the portfolio you need is a multiple of what you spend in a year, conventionally 25×, which comes from the 4% rule.

Target portfolio = Annual spending × 25

Lean FIRE      → small annual spending  → small target
Regular FIRE   → typical spending       → typical target
Fat FIRE       → large spending         → large target

So the first three labels are really just spending brackets. The other two — Coast and Barista — change something more interesting: whether you have to keep contributing, and whether you stop working at all.

Lean, regular, and Fat FIRE

These three are full financial independence: the portfolio covers everything, indefinitely, with no earned income required. They differ only in the lifestyle being funded. The figures below are the conventions people use in practice, not definitions anyone official has set.

Lean FIRE gets you out earliest, because it attacks the target from both directions — spending less means you save more each year *and* need a smaller multiple. The trade-off is margin. A lean retiree has less absolute buffer for a medical bill, a roof, or a decade of unhelpful markets, and less room to cut when something goes wrong.

Regular FIRE is the default case the original research describes: replace a normal middle-class income, indefinitely, from investments.

Fat FIRE is retiring without changing how you live. It is less a strategy than an arithmetic consequence — the target is large, so it usually requires a high income rather than a clever approach. There is nothing methodologically different about it.

Coast FIRE and Barista FIRE

These two are the genuinely useful ideas, because you hit them years — often more than a decade — before full financial independence.

Coast FIRE is the point where your existing portfolio, with no further contributions at all, will compound to your full FIRE number by your target retirement age. You still work, but only to cover current living costs. Everything you were putting aside for retirement is now free.

Coast number today = FIRE Number ÷ (1 + r/12)^T

Reached when: current portfolio ≥ coast number today

Barista FIRE is one step further along: your portfolio is large enough that part-time or lower-paid work covers the gap between your spending and what the portfolio can safely supply. The name comes from US workers taking coffee-chain jobs specifically for the employer health insurance — which makes it a much more American concept than the others. In countries with public healthcare, it is simply the observation that you need far less income once a portfolio is doing part of the work.

Which one are you actually aiming for

Most people pick a label before they have run a single number, then discover their spending puts them somewhere else entirely. Work it in this order instead:

1. 1Work out what you actually spend in a year. Not what you think you spend — what left your accounts over the last twelve months.
2. 2Multiply by 25. That is your regular FIRE number, and it already tells you which bracket you are in.
3. 3Ask whether you would keep working if you did not have to. If yes, Coast or Barista is a more honest target than full FIRE.
4. 4Only then decide whether to change your spending. Lowering it moves the target and raises your savings rate at the same time — it is the strongest lever you have.

Where the labels mislead

• Lean FIRE sounds like efficiency; it is really a smaller safety margin. The same 10% market drop costs a lean retiree a larger share of their flexibility.
• Fat FIRE sounds like an advanced strategy. It is the same strategy with a bigger number, usually reached through income rather than technique.
• Coast FIRE quietly assumes you can keep earning your living costs for years — through recessions, illness, and age discrimination. That assumption does a lot of unexamined work.
• Barista FIRE outside the US loses most of its original meaning, since the health-insurance problem it was named for does not exist in the same way.
• None of the labels tell you what to do next. They are a shorthand for a target, not a plan for reaching it.