Coast FIRE number at 25
Coast FIRE means you've invested enough that, even if you never save another dollar, compound growth alone carries you to a full retirement. At age 25, roughly $178,000 invested today would grow to a $1,250,000 nest egg by 65 (assuming a 5% real return) — enough to fund a comfortable retirement. After that, your paycheck only has to cover today's expenses.
Your Coast FIRE number at 25, by return assumption
Coast FIRE is sensitive to the return you assume over the 40 years to 65 — a higher real return means a smaller amount needs to compound:
| Return | Coast number | Growth |
|---|---|---|
| 4% real | $260,000 | 4.8× |
| 5% real | $178,000 | 7.0× |
| 6% real | $122,000 | 10.2× |
What Coast FIRE does and doesn't mean
Hitting your Coast FIRE number is a genuine milestone: your retirement is essentially on autopilot, and you gain the freedom to take a lower-paying but more fulfilling job, go part-time, or stop retirement contributions and spend that money now. It does not mean you can stop working — you still need income to cover current living expenses until you actually retire.
The number rests on two assumptions worth pressure-testing: the return you earn over the years to 65 (markets are uncertain, and a weak stretch early does outsized damage), and the target nest egg itself, which depends on your future spending. Model your own inputs to see how sensitive your coast number is to both.
What a forty-year runway really buys at 25
At 25 you have roughly four decades of compounding ahead of you, and that runway does almost all of the work. A comparatively small sum invested now can grow into a full retirement target with no further retirement contributions, simply because it has so long to compound. That is the quiet advantage of starting this early.
The real payoff is optionality. Once the coast number is funded you still work to cover today's expenses, but you no longer have to work to fund retirement — which frees you to take career risks a fully unfunded peer cannot: a lower-paid but meaningful job, a startup, a sabbatical, or a change of field.
Temper that with humility. The whole plan rests on a single assumed real return compounding uninterrupted for forty years, and small changes in that rate move the required number a great deal. Over so long and uncertain a horizon, recompute with a deliberately lower return, keep an emergency fund, and revisit the figure every few years rather than treating it as settled.
Common questions
What is the Coast FIRE number at 25?
About $178,000 invested at age 25, assuming a 5% real return, would grow to a $1,250,000 retirement nest egg by 65 with no further contributions. At a 6% real return it's closer to $122,000; at 4%, about $260,000.
Does Coast FIRE mean I can stop working?
No — it means you can stop saving for retirement. You still need enough income to cover your current living expenses until you retire; your retirement savings just grow on their own from here.
What return should I assume for Coast FIRE?
A real (after-inflation) return of about 5% is a common, moderate assumption for a stock-heavy portfolio over a long horizon. Because markets are uncertain, it's wise to check your number against a lower rate too.