Lean FIRE, Fat FIRE and Barista FIRE Calculator
FIRE is not one number. The same spending assumption produces four very different targets depending on how you plan to live and whether you keep earning. Here they are together.
Lean FIRE
Standard FIRE
Fat FIRE
Barista FIRE
- Taken off the target by your side income
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- Distance from Lean to Fat
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- Standard target as a multiple
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The four targets side by side
One spending assumption, four portfolios.
The same numbers as a table
Every target is your spending figure, adjusted, then divided by the withdrawal rate. The multiple column is the quickest way to see how far apart these four really are.
| FIRE type | Target portfolio | Multiple of your full spending | Annual spending the portfolio covers |
|---|
What each one actually assumes
The arithmetic is the easy part. The difference between these four is the life each one quietly assumes you will live, and the thing that has to go right for it to hold.
Lean FIRE
What it assumes. A deliberately small budget, here 70% of the figure you entered. In practice that usually means housing that is paid off or genuinely cheap, one car or none, and a household that is good at saying no to lifestyle creep.
Who it suits. People whose spending is already low by choice, and who would rather have their time back sooner than have more room in the budget later.
The risk. A lean budget has almost no slack. A health event, a new roof, or a stretch of higher prices has to come from somewhere, and there is not much left to cut. Plenty of people who plan lean end up working longer or picking up income anyway, which is really Barista FIRE with extra steps.
Standard FIRE
What it assumes. The portfolio covers exactly the spending you entered, with no paycheck and no side income. This is the plain FI number, and it is the reference the other three are measured against.
Who it suits. Almost everyone, as a planning anchor. It is the only one of the four with a definition people agree on.
The risk. It is exactly as good as your spending figure. If the number you entered is what you spend today, and life gets more expensive later (children, care for a parent, health coverage before Medicare), the target moves and you find out late.
Fat FIRE
What it assumes. Half again as much spending, 150% of your figure. Travel, a larger home, private health coverage, generosity, and enough slack that a bad year is an inconvenience rather than a crisis.
Who it suits. High earners who do not want to trade lifestyle for time, and anyone whose plan has to absorb large, unpredictable costs without flinching.
The risk. The target is 50% bigger, so it takes materially longer to reach, and those are real years of your life. Fat FIRE fails as a plan less often because the arithmetic was wrong and more often because the target kept moving: spending rises to meet income, and the finish line moves with it.
Barista FIRE
What it assumes. You keep earning something after you leave full-time work, so the portfolio only has to fund the gap between your spending and that income. The name comes from the idea of a part-time job that carries health benefits.
Who it suits. People who want out of full-time work well before a portfolio can carry everything, and who have work they are genuinely willing to keep doing.
The risk, and it is worth naming twice. First, it depends on continuing to earn. That is a bet on your health, on the job market, and on still wanting to show up in ten years. If the income stops, the portfolio was never sized to cover the whole budget. Second, health coverage is often the real reason for the job. Employers change benefit eligibility and hours thresholds, and a plan that quietly depends on one employer's coverage has a single point of failure in it.
How these labels are actually used
Read this before you take any of the four numbers above too seriously.
None of these labels has a fixed definition
Lean, Fat and Barista FIRE are community shorthand from forums and blogs, not defined terms. Different people draw the lines in different places. Some define Lean FIRE by an absolute figure (spending under roughly $25,000 to $40,000 a year for a household) rather than as a share of your own budget. Fat FIRE is sometimes described by portfolio size, or simply as "comfortably more than enough", rather than by any multiple.
The 70% and 150% used here are round, common, and easy to reason about. They are a starting point, not an authority. If the Lean or Fat figure on this page does not describe the life you actually have in mind, the honest fix is to change the spending figure at the top of the page and read the standard number, because that is the one with real arithmetic behind it.
Coast FIRE and Barista FIRE answer different questions
They get compared constantly, and they are not alternatives. Coast FIRE asks whether the balance you already have can grow into your number on its own, so you can stop adding to it while you carry on working. Barista FIRE asks how much smaller the portfolio needs to be if you keep earning after you leave full-time work. One is about when you can stop saving; the other is about how much you need before you can stop working full-time. You can be both at once, and many people are.
Which number should you plan around?
The standard one, with the others as context. It is the only target that does not depend on a lifestyle assumption someone else picked or on income that has to keep arriving. Lean tells you the floor, Fat tells you what breathing room costs, and Barista tells you how much a few years of part-time work is worth to your target. None of the four is a plan on its own: what makes any of them real is knowing what you actually spend, which is a different problem, and the one Ember exists to solve.
Stop re-typing your numbers
This page is a snapshot from figures you keyed in by hand. Ember keeps the same numbers current on their own: every account in one ledger, real net worth, and spending you can actually trust.
Ember is in private beta and invite-only right now.
This tool provides estimates for general planning purposes only, not personalized financial or tax advice. It relies on simplifying assumptions (see "How this is calculated" below) that will not match your actual results. Consult a qualified professional before making financial decisions.
How this is calculated
The formula
lean number = (annual expenses × 0.70) ÷ (withdrawal rate ÷ 100)
standard number = annual expenses ÷ (withdrawal rate ÷ 100)
fat number = (annual expenses × 1.50) ÷ (withdrawal rate ÷ 100)
barista gap = max(0, annual expenses − part-time income)
barista number = barista gap ÷ (withdrawal rate ÷ 100)All four are the same calculation: take the spending the portfolio has to cover and divide it by the withdrawal rate. At 4% that is 25 times the spending, at 3% it is about 33 times, and at 5% it is 20 times. The only thing that changes between the four is which spending figure goes in the top of the fraction.
Barista FIRE is the one exception worth spelling out: your part-time income is subtracted from your spending first, and only the remainder is priced. If the income is larger than your spending, the gap is zero and so is the target, which is a real answer rather than an error.
Where 70% and 150% come from
Convention, and nothing more. There is no standards body for these words. We picked two round multipliers that sit either side of the standard number and are easy to reason about. Treat them as a way to see the shape of the spread rather than as anyone's definition. If you have a real lean or fat budget in mind, put that figure in the expenses box and read the standard number instead.
What the part-time income assumes
The calculation treats your part-time income as permanent and as keeping pace with inflation, for as long as the portfolio has to last. That is a strong assumption, and it is the main reason a Barista FIRE target looks so much friendlier than a standard one. In reality that income has an end date you do not know yet, and when it ends the portfolio has to cover the full amount. It is worth checking what your standard number is even if you are planning around the Barista one.
What this does not account for
- Health coverage. Nothing here prices insurance. For many people it is the single largest line item between leaving full-time work and Medicare, and it is often the actual reason a Barista FIRE job exists.
- Taxes. Part-time income is taxable, and so are withdrawals from traditional accounts. If your spending figure is what you need after tax, every target here is too small.
- Other income. Social Security, a pension, or rental income all reduce what the portfolio has to cover, and none of them appear in these numbers.
- Reaching the money. A target says nothing about which accounts it sits in. Getting at balances held in traditional retirement accounts before 59½ is its own problem, and the Roth conversion ladder calculator prices the most common way through it.
- Sequence of returns. A fixed withdrawal rate hides the fact that a poor first decade is far more damaging than a poor last one. The safe withdrawal rate explorer is the better tool for that question.
Shared assumptions
- Returns are real, not nominal. Every return figure on this page is already inflation-adjusted, so all dollar amounts are in today's money. There is no separate inflation input to set.
- Returns are smooth. The same return is applied every year. Real markets are not smooth, and the order in which good and bad years arrive changes outcomes materially.
- No taxes, fees, or lumpy spending. Investment fees, taxes on withdrawals, one-off costs, and changes in your spending over time are not modelled.
- Nothing leaves your browser. The whole calculation runs client-side. We do not receive, log, or store anything you type.