Worked example
Example with the default numbers — change them above.
Your age today: 30 · Age you want to retire: 55 · Monthly spending today: ₹60,000 · Investments today: ₹40,00,000 · Monthly saving until you coast: ₹30,000 · Assumed return per year: 11% · Inflation per year: 6% · Withdrawal rate in retirement: 3.5%
You need ₹64.99 L invested today to coast to your FIRE number of ₹8.83 Cr by 55; you have ₹40 L. Saving ₹30,000 a month, you can stop saving at age 39.
| You can stop saving at | Age 39 · In 9 yrs |
|---|---|
| Coast FIRE number today | ₹64.99 L · You have 62% of it |
| FIRE number at 55 | ₹8.83 Cr · ₹2.06 Cr in today's money |
| If you stop saving today | ₹5.43 Cr · At 55: 62% of the FIRE number |
| Shortfall today | ₹24.99 L · Extra needed invested now to coast |
How the Coast FIRE Calculator works
- Your monthly spending is inflated to your retirement age, and divided by your withdrawal rate to give the FIRE number at retirement.
- The Coast number at any age is that FIRE number discounted back at your expected return: what you need invested then so growth alone gets there.
- If your corpus today is at least the Coast number, you are already coasting.
- Otherwise your saving is added month by month, and the first month your balance meets that month's Coast number is the age you can stop saving.
- The chart then lets that balance grow untouched to retirement, so you can see it land on the FIRE number.
Coast FIRE number
FIRE number at retirement = 12 × S × (1 + i)^n ÷ w
Coast number today = FIRE number ÷ (1 + r)^n
S = monthly spending today; i = inflation; w = withdrawal rate
r = expected yearly return; n = years until retirementAssumptions and limits
- The same return every year until retirement; a weak decade early on can push the coast age out a long way.
- Your spending rises exactly with the inflation you enter.
- After you stop saving you do not withdraw anything until retirement; your income covers your spending.
- Tax is not modelled; enter returns after costs.
- The withdrawal rate stands in for the retirement years; test it in the Monte Carlo simulator.
Frequently asked questions
What is Coast FIRE and how is the Coast FIRE number calculated?
Coast FIRE means you have invested enough that, with no further saving, growth alone will reach your FIRE number by retirement. The Coast number is the FIRE number at retirement divided by (1 + return) raised to the years left. For example, at 11% a year for 25 years, about ₹65 lakh invested today grows to about ₹8.8 crore.
How is Coast FIRE different from regular FIRE?
With regular FIRE your investments already pay your living costs, so you can stop working. With Coast FIRE you can stop saving, but you still need income to cover today's spending until your retirement age. It is a milestone on the way to FIRE that gives freedom to take a lower-paid, more enjoyable or part-time job without derailing retirement.
Why is Coast FIRE so sensitive to the return I assume?
Because the Coast number discounts your target over many years, and small changes in the rate compound. Over 25 years, the difference between 9% and 11% a year changes the growth multiple from roughly 8.6 times to 13.6 times. The notice under the result shows your Coast number at a return 2 points lower, which is a sensible stress test.
Do I still need to work after reaching Coast FIRE?
Usually yes, just with more freedom. You need income that covers your spending until retirement, without touching the corpus. Many people use Coast FIRE to switch careers, work fewer hours or take a sabbatical. If you start drawing on the corpus before retirement, the coast maths no longer holds, and you are closer to Barista FIRE.
Should EPF and PPF count towards Coast FIRE?
Their current balances count, because they keep earning interest while untouched, but at their own rates (EPF 8.25% for FY2025-26), not equity returns, and EPF interest stops 36 months after you retire at 55 or later. Future EPF contributions are extra saving, so if you stay salaried after coasting, your corpus may end up larger than planned. PPF needs a minimum deposit each year to stay active, which is small. Lock-ins matter less for Coast FIRE, since the money is not touched until retirement.
What return should I assume for Coast FIRE in India?
Use a return you would be comfortable relying on for decades, after costs, for your actual mix of equity, debt and other assets. The Nifty 50 total-return index has delivered about 12% a year over 20 years, but future returns may differ, so 10% or less is a safer plan for a mostly-equity portfolio and less again for a balanced one. Because Coast FIRE is so sensitive, it is safer to plan with a lower figure and treat anything extra as a bonus.
Sources
- Ministry of Statistics and Programme Implementation: consumer price index (inflation) data
- Reserve Bank of India: inflation, interest-rate and household-finance statistics
- AMFI: mutual fund data and investor education (SIP and SWP basics)
- SEBI: investor education on market risk
Logic and rates last verified on .
Next step: related calculators
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Retirement & FIRE FIRE Calculator
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Retirement & FIRE Barista FIRE Calculator
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Retirement & FIRE Lean FIRE Calculator
How soon could I retire on a frugal budget?
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Retirement & FIRE FIRE Monte Carlo Simulator
What are the odds my retirement money lasts?
Guides that go deeper
See worked examples
The corpus and monthly SIP to retire at 40, 45, 50 or 55 on ₹20,000 to ₹2 lakh a month.
- How much corpus do I need to retire at 40 with ₹20,000 monthly expenses? — Corpus ₹1.23 Cr, SIP ₹44,500 a month
- How much corpus do I need to retire at 40 with ₹30,000 monthly expenses? — Corpus ₹1.84 Cr, SIP ₹66,500 a month
- How much corpus do I need to retire at 40 with ₹50,000 monthly expenses? — Corpus ₹3.07 Cr, SIP ₹1,11,000 a month