Coast FIRE vs Barista FIRE: The Decision Math

Coast FIRE and Barista FIRE both promise the same thing: a way out of full-time saving before you hit your full FIRE number. Most comparisons stop at the definitions. That's the easy part.

The harder question is which milestone you'll reach first, what each one still asks of you, and what happens to each plan when the market drops right after you make the switch. This post answers those with one household and real arithmetic.

The two definitions, side by side

Coast FIRE means you've saved enough that you can stop contributing entirely and your portfolio will still grow into your full FIRE number by a target age. You keep working, but only to pay your current bills. You don't withdraw anything.

Barista FIRE means your portfolio is big enough to cover the gap between your spending and what a part-time or lower-stress job pays. You start withdrawing now, and the job carries the rest.

The short version: Coast FIRE buys you freedom from saving. Barista FIRE buys you freedom from full-time work. They are not two sizes of the same thing.

The example household

Meet Alex, 35. Alex has $250,000 invested, spends $50,000 a year, and saves $30,000 a year working full time.

Assumptions for every number below:

• A 5% real return (after inflation), applied evenly each year
• A 4% withdrawal rate, so the full FIRE number is 25 × $50,000 = $1,250,000
• A Coast target age of 60
• All figures in today's dollars, before taxes

If you want to check the formula behind that first number, see the FIRE number explained in plain English.

The Coast number shrinks with every year you have left

Your Coast number is your FIRE number discounted back by the years of growth still ahead:

Coast number = FIRE number ÷ (1 + real return)^(years until target age)

For Alex, with a target age of 60:

The target moves up every year you wait, because there's less time left to compound. Saving $30,000 a year, Alex's portfolio passes the Coast line at age 40, with $484,839 against a requirement of $471,112.

From then on, Alex could stop saving entirely. But Alex still needs a job that pays the full $50,000 a year in spending, every year, for 20 more years.

The Barista number depends on the paycheck, not the calendar

The permanent Barista FIRE number is:

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

Say Alex finds part-time work paying $24,000 a year. The gap is $26,000, so the Barista number is $26,000 ÷ 0.04 = $650,000. Alex reaches it at age 43, with $655,837.

At that point Alex can drop to part-time work, withdraw about $26,000 a year (a 4% withdrawal rate), and never save another dollar. For a deeper look at the lifestyle side, see Barista FIRE: pros, cons and how to start the transition.

Alex's milestones in one table

So for Alex, Coast comes first. That isn't a universal rule. It depends on how much the part-time job covers.

The crossover: when Barista comes first

Compare the two formulas at the same age. At 40, with 20 years to go, the Coast number is about 37.7% of the full FIRE number ($471,112 ÷ $1,250,000). The Barista number is the full number times the share of spending the portfolio still has to cover.

So the Barista number drops below the Coast number once part-time income covers more than about 62% of spending. For Alex, that's a job paying roughly $31,200 a year or more.

Two quick rules fall out of that:

• Younger, long horizon, modest part-time pay: Coast usually arrives first.
• Older, short horizon, or a part-time job that pays well: Barista usually arrives first.

The return assumption matters a lot for Coast and much less for Barista. Here's Alex's Coast number at 40 under different real returns:

At 7%, Alex's $250,000 already clears the age-35 Coast number of $230,311. One percentage point of assumed return moves Alex's Coast date by three to four years. The Barista number doesn't use the return at all; it only uses the withdrawal rate. If you aren't confident in your return assumption, that's a point in Barista's favor as a planning target.

The hybrid most people actually mean

Many people who say "Barista FIRE" don't mean part-time work forever. They mean part-time work until a traditional retirement age, with the portfolio still growing to the full FIRE number by then.

That needs a bigger portfolio than the permanent version, because the portfolio has to cover the gap and keep compounding toward $1.25 million. For Alex, still targeting 60:

Notice how little the part-time pay moves the switch date here: an extra $12,000 a year in pay buys Alex two years. Time in the market does most of the work.

The stress test: a 30% drop the year after you switch

Averages hide the real difference between these plans. So drop the market 30% in the first year after each switch, then go back to 5% a year.

Coast at 40. Alex's $484,839 falls to about $339,000. With no contributions, it grows to $857,615 by 60, which is $392,385 short of the $1.25 million target. The fix is easy, though: Alex is still working full time. Saving about $11,900 a year for those 20 years closes the gap. Coast FIRE fails softly because you never stopped earning, and you never sold anything at a low price.

Permanent Barista at 43. Alex withdraws $26,000 in the crash year and every year after. Without the crash, the portfolio keeps growing and sits near $980,000 by 68. With the crash, it shrinks steadily and runs out at about 80. Not a disaster at 43, but no longer a plan that lasts for life.

Hybrid Barista at 47. Starting from $926,478, the crash plus $26,000 a year in withdrawals leaves $704,137 at 60, against a target of $1.25 million. Alex would need to work longer, earn more or spend less to recover.

The pattern is the important part. Coast FIRE carries return risk but no withdrawal risk. Barista FIRE carries both, because selling shares in a down market locks in the loss. The safety valve in Barista is the job: the more hours you can add back in a bad year, the safer the plan.

So which should you aim for?

Choose Coast FIRE as your next milestone if:

• You like your work, or at least don't mind it, and want to stop saving more than you want to stop working
• You're in your 20s or 30s, with decades of compounding left
• Your employer's health insurance and benefits matter to you
• You'd rather not depend on withdrawals while you still have a paycheck

Choose Barista FIRE as your next milestone if:

• Full-time work is the problem, and a lighter role would change your life
• You have a realistic part-time income in mind, ideally one that covers a large share of spending
• You can flex hours up or spending down in a bad market year
• You've priced health insurance without a full-time employer. For many people in the U.S., that's the line item that decides it

You also don't have to pick one forever. A common path is to reach Coast, keep working full time a few more years while the portfolio grows, then step down to part-time once the hybrid Barista number is in reach. For Alex, that's Coast at 40 and a switch to $24,000-a-year work around 47. Our guide to Coast FIRE and who it suits covers the early half of that path.

How to run your own numbers

You need four inputs, and they should be real ones:

1. Annual spending. Not a guess. Your actual last 12 months, minus anything that will end before you switch.
2. Invested balance, excluding your home and cash you'll need.
3. A real return assumption. Test at least two, such as 4% and 6%.
4. Part-time income you could actually earn, after any costs of doing that work.

The free FIYR FIRE calculator shows your Coast FIRE number by age alongside your full FIRE number, with no account needed. Inside the FIYR app, the FIRE dashboard has a Coast FIRE card and a Barista FIRE card. Coast shows the age you could stop contributing based on your linked investment accounts and their weighted return. Barista lets you enter the part-time income you'd earn and shows the earliest age you could switch and still reach your full FIRE number by your chosen retirement age. That is the hybrid version from the table above. Both start from your actual spending in your linked accounts, which you can override with a custom figure.

FIYR's projections use steady average returns, so run the crash test above yourself before you hand in your notice.

Frequently asked questions

What is the difference between Coast FIRE and Barista FIRE? Coast FIRE means you can stop saving because your portfolio will grow into your FIRE number on its own, but you still earn all of your spending. Barista FIRE means your portfolio covers the gap between your spending and a part-time income, so you start withdrawing now.

Which comes first, Coast FIRE or Barista FIRE? It depends on your age and the part-time pay. In our example at age 40 with 20 years to go, Coast came first unless the part-time job covered more than about 62% of spending.

Is Barista FIRE riskier than Coast FIRE? Usually, yes. Both depend on returns, but Barista also depends on withdrawals, and selling during a downturn makes a bad year more damaging. In our example, a 30% drop left the Coast plan short but easily fixable by saving about $11,900 a year, while the same drop cut the Barista plan's lifespan to about age 80.

How do I calculate my Coast FIRE number? Divide your FIRE number by (1 + real return) raised to the number of years until your target age. With a $1.25 million FIRE number, a 5% real return and 20 years to go, that's $471,112.