Types of FIRE: Lean, Fat, Coast and Barista Explained

FIRE started as one idea with one number: save enough that your investments cover your spending, and paid work becomes optional. Then it acquired adjectives. Lean, Fat, Coast, Barista, and a long tail of variants that mostly exist to make a spreadsheet feel like an identity. Underneath, they are all the same arithmetic pointed at different targets.

The one number underneath all of them

Every version of FIRE is built on a single relationship: the portfolio you need is your annual spending divided by the rate you plan to withdraw. At a 4% withdrawal rate that is twenty-five times your spending. At 3.5% it is about twenty-nine times; at 3% it is thirty-three.

FIRE number = annual spending ÷ withdrawal rate

The flavours differ in only two ways: how much spending they assume, and whether you are drawing on the portfolio yet. That is genuinely all. Once you see that, the taxonomy stops being intimidating.

Lean FIRE

Lean FIRE targets a deliberately small spending number — commonly framed as living on a below-average household budget, often somewhere near $25,000–$40,000 a year for a single person in a low-cost area. The portfolio required is correspondingly small, which is the entire appeal: at a 50% savings rate, a lean target can be reached in well under twenty years from zero.

The trade is flexibility. A lean plan has very little slack in it, so an unexpected medical bill, a relocation, or a decade of higher-than-expected inflation eats the margin quickly. Lean FIRE works best for people who have already lived on the number for several years and know it is genuinely comfortable rather than aspirational.

Fat FIRE

Fat FIRE is the same maths with a generous spending assumption — often $100,000 a year or more, implying a portfolio north of $2.5m at 4%. The point is not luxury for its own sake; it is that the plan carries enough slack to absorb bad surprises without anyone having to go back to work.

The obvious cost is time. A higher target needs either a much higher income, a much longer accumulation period, or both. In practice Fat FIRE is usually reached by people who kept working through a high-earning decade rather than by people who saved more aggressively.

Coast FIRE

Coast FIRE is the first genuinely different structure. Instead of asking how much you need to stop working, it asks how much you need to stop saving. Once your invested net worth is large enough that ordinary compounding will carry it to a full retirement number by your target age, you can lower your savings rate to zero and simply cover your living costs.

Coast number = FIRE number ÷ (1 + real return)^{years to retirement}

Because compounding does the remaining work, the coast number is dramatically smaller than the full one. Roughly $181,000 invested at thirty compounds to about $1m by sixty-five at a 5% real return. You are not retired — you still work — but you have bought the right to take a lower-paid job, drop to four days, or change careers without derailing retirement. Run your own numbers with the Coast FIRE calculator.

Barista FIRE

Barista FIRE sits between Coast and full FIRE. Part-time work covers part of your spending; the portfolio covers the rest, starting now. The name comes from taking a coffee-shop job for the health insurance, but the structure applies to any reliable part-time income.

Barista number = (annual spending − part-time income) ÷ withdrawal rate

The leverage is large, because at a 4% withdrawal rate every unit of recurring income replaces twenty-five units of portfolio. The critical distinction from Coast FIRE is that you are drawing down, which means sequence-of-returns risk is live and starts early. There is more on this in the Barista FIRE explainer.

The variants side by side

Multiples shown at a 4% withdrawal rate. Coast FIRE has no fixed multiple — it depends entirely on how many years of compounding remain.

The same person, four targets

Take someone aged 32 who spends $48,000 a year, has $150,000 invested, saves $30,000 a year, and assumes a 5% real return and a 4% withdrawal rate. Here is what each flavour asks of them.

Which one are you actually aiming for?

Most people pick a label first and reverse-engineer the numbers, which is the wrong order. Three questions get you to the right one faster.

• Do you want to stop working, or stop needing to? If the honest answer is the second, Coast FIRE gets you there years earlier and carries far less risk.
• Is your current spending a number you have actually lived on? Lean targets built on a hypothetical budget tend to fail on contact with reality.
• How replaceable is your income? The more easily you could earn again, the more aggressive a target you can safely run, because your fallback is real.

The labels are a vocabulary, not a hierarchy. Nobody is doing FIRE wrong by choosing a different point on the same curve.

The variant nobody names

There is a fifth option that gets far less attention than it deserves: reaching financial independence and then continuing to work because you want to. The portfolio removes the coercion without removing the work. In surveys of people who have reached FI, a large share keep earning in some form — and they report the change in how work feels, not the absence of it, as the thing that mattered.

Questions, answered