What Is Coast FIRE?
Coast FIRE is the point where your investments are big enough that compounding can carry them to your full retirement target without another rupee of contributions. You have not retired yet — you have simply made the heavy lifting optional.
What Coast FIRE means
In traditional FIRE, the goal is a portfolio large enough to fund your retirement starting today. Coast FIRE changes the question: instead of "how much do I need now?", it asks "how much do I need to stop contributing and let growth finish the job?". The phrase comes from the idea that once you reach the number, you can coast — keep working to pay today's bills while your existing investments quietly compound toward the target. Contributions become optional rather than essential.
Two levers drive the maths: the expected return on your portfolio and the number of years before you want to retire. More time means a smaller coast number, because growth has longer to do its work.
Coast FIRE vs traditional FIRE
Both approaches aim at the same destination — a corpus that supports you in retirement — but they differ on effort and timing:
- Traditional FIRE: you save a large sum first, then stop working. Contributions do most of the work, with growth helping along the way.
- Coast FIRE: you save a smaller sum early, then let compounding do the heavy lifting while you keep earning day-to-day income.
- Timing: traditional FIRE targets an immediate stop; Coast FIRE targets a future one, with work continuing in the gap.
- The bar: Coast FIRE has a much lower starting point, but it depends more heavily on the return you assume and the years available.
You can think of Coast FIRE as the halfway milestone on the road to full FIRE. Reach it, and the finish line starts moving toward you on its own.
How the calculation works
The coast number is a simple present-value calculation:
coast number = target corpus ÷ (1 + expected return) ^ (years to retirement)
In words: take the full amount you want at retirement, then discount it back to today using your assumed growth rate and the number of years you have. The formula assumes one thing — that from today onwards you make no further contributions and the money simply grows. The variables that move the result the most are the return you assume and your time horizon. A higher expected return or a longer runway shrinks the number; a conservative return or a near retirement age pushes it up.
The inputs you need
Four inputs drive the result: your target retirement corpus (the amount you want when you stop working — often your annual retirement spending × 25), your current age, your planned retirement age, and the annual return you expect on your investments. If you want to be more careful, add an inflation assumption so your target is expressed in future rupees. That is it — the calculation is deliberately simple, and that simplicity is both a strength and a limitation.
A worked example
For illustration: suppose you want a ₹3 crore corpus at age 55 and you are 35 today, giving 20 years of growth. Assuming a 10% annual return, your coast number is roughly ₹3 crore ÷ (1.10)^20 ≈ ₹45 lakh. Reach ₹45 lakh today, and — at 10% a year with no more contributions — the money should grow to about ₹3 crore by 55. Nudge the return down to 8% and the same goal needs closer to ₹64 lakh. The example is hypothetical; your real number depends on the assumptions you choose.
What Coast FIRE does NOT solve
Coast FIRE is about the retirement portfolio; it says nothing about the years in between. Reaching your coast number does not mean you can quit your job, because the portfolio is not ready to pay your living expenses yet — and it will not, until it compounds into the full target. You still need a source of day-to-day income, whether that is full-time work, freelance projects or a side business.
Coast FIRE also assumes the market cooperates. A long stretch of low returns can push the finish line later, which is exactly the kind of risk that a sequence-of-returns discussion and a Monte Carlo simulation are designed to expose.
Educational content, not financial advice. This page explains Coast FIRE in general terms to help you understand the idea. It is not personalised advice, and nothing here should be read as a guarantee of future returns. For decisions involving real money, consider speaking with a qualified professional.
Frequently Asked Questions
What is Coast FIRE?
Coast FIRE is the point where your investments are large enough to grow into your full retirement corpus by your target retirement date, even if you never add another contribution. You keep working for daily expenses while compounding does the heavy lifting.
How is Coast FIRE different from FIRE?
Traditional FIRE targets a portfolio that can support you right away. Coast FIRE targets a smaller portfolio that will grow into full FIRE later, so you continue working — just with no pressure to keep saving aggressively.
How much do I need for Coast FIRE?
It depends on your target corpus, the return you assume and your years to retirement. The coast number is your target corpus discounted back to today: target corpus ÷ (1 + expected return) raised to the years to retirement.
What rate of return should I assume?
A reasonable figure depends on your asset mix. For a long-horizon, equity-heavy portfolio a common planning range is 8–12% a year, but returns are uncertain, so it is wise to also test a conservative low figure.
What happens after I reach Coast FIRE?
Your contributions become optional. You can keep working to pay today's costs while the portfolio compounds, or keep saving to shorten the runway and add buffer. You are not retired yet — you have simply made reaching the goal no longer dependent on new money.
Can I do Coast FIRE in India?
Yes. The maths is currency-neutral, and many Indian savers combine equity-heavy SIPs for growth with EPF, PPF and NPS for stability. Just be careful with the return assumption you use.