What Coast FIRE actually is

Full financial independence means the corpus covers your expenses forever. Coast FIRE means something narrower and far more reachable: the corpus is large enough that compounding alone gets it to the full number by the age you picked. From that point, every rupee you invest is optional.

The distinction matters because it changes what the number is for. A full FIRE number tells you when you can stop working. A Coast FIRE number tells you when you can stop optimising — when you can take the lower-paid job you actually want, or drop to four days a week, without breaking the retirement plan. That decision usually arrives long before the retirement one.

Why the gap between the two is so large

Compounding is back-loaded. A corpus growing at a real 5.7% doubles roughly every twelve and a half years, so the last decade before your target age does far more work than the first. Twenty-three years of untouched compounding turns roughly a quarter of the target into the whole of it.

Which is also why the number is sensitive to the target age. Push independence out by five years and the Coast FIRE corpus drops by roughly a quarter, because compounding gets five more years to work. Pull it in by five and it climbs by about a third. The withdrawal rate you assume shifts it in the same way — see the full FIRE calculator for why 3–3.5% is a more defensible assumption in India than the American 4%.

Why a lower withdrawal rate needs a bigger corpus

The withdrawal rate is not how much you spend. Your spending is the figure in the first field, and it does not move when you change the rate. The rate is what share of the corpus that spending represents — so the same spending, drawn more gently, has to come out of a larger pot.

On ₹2,00,000 a month, which is ₹24 lakh a year:

Identical income in all three rows. Stated as a multiple rather than a percentage the direction stops being surprising: 4% is 25× your annual expenses, 3.5% is 28.6×, and 3% is 33.3×. A more cautious plan costs more, not less.

Where the rule comes from

The direction itself is not a research finding. It is division: your corpus is annual expenses divided by the rate, so halving the rate doubles the corpus.

The research settles two different questions. The first is the definition — that the withdrawal rate is a percentage of the portfolio at retirement, taken in year one and then adjusted for inflation rather than recalculated each year. That comes from William Bengen’s 1994 paper, which found 4% was the highest rate that survived every 30-year window in the American data, and was confirmed shortly after by the Trinity study.

The second is which rate you should actually pick, and here the American number is the wrong one to inherit. Indian data is shorter, more volatile and inflates faster, and the work that tests withdrawal rates against it — Raju and Saraogi, then Raju on 1992–2024 — lands lower than 4%. That is why this calculator offers 3% and 3.5% at all, and why the full FIRE calculator argues for them. Every source is listed at the foot of this page.

What this does not tell you

Coast FIRE is a projection built on a smooth real return, and no portfolio delivers one. A sequence of poor early years leaves you short even if the long-run average holds, and the model has no way to show that. Treat the number as a threshold to re-check annually, not a finish line to cross once.

It also assumes you genuinely leave the corpus alone. Coasting while dipping into the same pot for a car or a wedding is not coasting; it is spending. If the money is going to be needed, it does not belong in this calculation.

Sources

• William Bengen — Determining Withdrawal Rates Using Historical Data, Journal of Financial Planning (1994)
• Wade Pfau — Safe Withdrawal Rates for Retirement and the Trinity Study, a synthesis of Cooley, Hubbard and Walz (1998)
• Rajan Raju and Ravi Saraogi — Balancing Acts: Safe Withdrawal Rates in the Indian Context (2024)
• Rajan Raju — Safe Withdrawal Rates in India, 1992–2024 (2025)

Questions worth asking

What is Coast FIRE in simple terms?

Coast FIRE is the corpus at which you can stop adding money and still reach your full financial independence number by your target age, purely through compounding. You keep working to cover living costs, but you no longer need to invest. It is typically reached ten to twenty years before full independence.

How is Coast FIRE different from Lean FIRE?

Lean FIRE is a smaller target — full independence on a reduced lifestyle, often 70% of current spending. Coast FIRE is the same full target, reached later without further contributions.

What real return should I assume for Coast FIRE?

The calculator derives it from your nominal return and inflation, which is more honest than assuming a real rate directly. An equity-heavy Indian portfolio assumed at 11% nominal against 5% inflation gives roughly 5.7% real. Lower it if your allocation includes significant debt, and re-check the assumption rather than inheriting it.

Does my house count towards Coast FIRE?

Not if you live in it. A home you occupy produces no withdrawable income, so it cannot fund expenses in retirement without being sold or mortgaged. Count invested assets: mutual funds, stocks, EPF, NPS, and property you genuinely intend to sell or rent out.

Can I go backwards from Coast FIRE?

Yes. A market fall can drop you below the threshold, and inflation running above your assumption raises the target. That is why the number is worth recalculating annually rather than declaring reached once.

The rest of the calculators

Calculator and assumptions last reviewed 5 August 2026.

This is an explanation of arithmetic, not advice about your money. TLDR Money is not a registered investment adviser and earns nothing from any product mentioned here. Figures are illustrative; your own numbers, taxes and circumstances will differ.