Coast FIRE Calculator

Retirement

Coast FIRE is the lump sum you need invested today so that compounding alone grows it to your full FIRE number by retirement — no more contributions required.

Free · No sign-up · Private6 min readUpdated 27 July 2026

In short: Your Coast FIRE number is the present value of your FIRE target: the amount invested today that, left completely untouched, compounds up to the corpus you need at retirement. Once your portfolio hits it, you can stop investing for retirement and only need to cover current living costs.

Your inputs

Results

Coast FIRE number

₹7,86,291

Lump sum needed invested today

FIRE target at retirement

₹1,80,00,000

25× annual expenses

Projected value of current investments

₹4,57,84,593

At age 60

Surplus vs coast number

₹12,13,709

Above the coast number

Coasting to your FIRE number

Your current investments compounding vs the coast target that lands on the FIRE number.

Year-wise growth of current investments

Year-wise growth of current investments
Year	Age	Projected value
0	30	₹20,00,000
1	31	₹22,20,000
2	32	₹24,64,200
3	33	₹27,35,262
4	34	₹30,36,141
5	35	₹33,70,116
6	36	₹37,40,829
7	37	₹41,52,320
8	38	₹46,09,076
9	39	₹51,16,074

Your existing corpus compounds annually at the expected return with no new contributions.

Formula

Coast FIRE number = FIRE target ÷ (1 + r)^n; FIRE target = Annual expenses ÷ (Withdrawal rate ÷ 100)

FIRE target: Corpus needed at retirement (25× expenses at 4%)
r: Expected annual return (as a decimal)
n: Years from today until retirement
(1 + r)^n: The growth multiple compounding provides over the horizon

Step-by-step calculation

Worked with the default values.

1
Years to retirement
60 − 30
= 30 yrs
2
FIRE target at retirement
₹7,20,000 ÷ (4% ÷ 100)
= ₹1,80,00,000
3
Coast FIRE number (today)
₹1,80,00,000 ÷ (1 + 11%)^30
= ₹7,86,291
4
Already coasting
Current investments ≥ coast number
= Yes — stop if you like

How it works

Your annual retirement expenses are divided by the withdrawal rate to size the full FIRE target you need at retirement.
That target is discounted back to today at your expected return over the years to retirement — the result is your coast number.
If your current investments already meet or exceed the coast number, compounding alone finishes the job and you can stop contributing for retirement.

Examples

Age 30, retiring at 60, ₹7.2 lakh annual expenses, 11% return, 4% rule

FIRE target is ₹1.8 crore; the coast number today is roughly ₹8 lakh, since 30 years of compounding does the rest.

Same plan but starting at age 45 with only 15 years to retire

The coast number jumps to about ₹38 lakh — far less compounding time means far more must be invested up front.

Understanding the Coast FIRE Calculator

What Coast FIRE actually means

Coast FIRE is a milestone on the road to financial independence. It is the moment your invested corpus is large enough that, even if you never add another rupee, ordinary compounding will grow it to your full FIRE number by the time you retire. You are not financially independent yet — you still work to pay today’s bills — but your *retirement* saving is finished. From here, your money coasts.

The number itself is simply the present value of your FIRE target. First size the corpus you need at retirement: annual expenses divided by your safe withdrawal rate, which at 4% is the familiar 25× rule. Then discount that target back to today at your expected return over the years remaining. A ₹1.8 crore target 30 years away at 11% shrinks to a coast number of only about ₹8 lakh, because three decades of compounding do almost all the work.

Why starting age dominates

Because the target is compounded over the whole horizon, time is the decisive lever. The same ₹1.8 crore goal needs roughly ₹8 lakh at age 30 but around ₹38 lakh at age 45 — the shorter runway leaves far less room for growth. This is the core lesson of Coast FIRE: money invested in your twenties is worth vastly more than the same amount invested later, so front-loading is enormously powerful.

What you gain, and what to watch

Reaching Coast FIRE is liberating. Once your portfolio crosses the coast number, you can, in principle, stop saving for retirement and only earn enough to cover current expenses — the foundation of lifestyles like Barista FIRE, where lighter or part-time work funds daily life while the corpus coasts.

The catch is that the whole plan leans on one return assumption held over decades. A long stretch of weak markets after you stop contributing can leave you short, with less time to recover. The defences are practical: assume a conservative return so your coast target has a built-in cushion, recheck your progress every year or two, and stay ready to resume investing if reality underperforms your plan. Use this calculator to test how age, expected return and expenses move the coast number, and find the point where compounding can safely finish the job for you.

Pros

Frees you from mandatory retirement saving far earlier than full FIRE.
Lets you downshift to lower-paying, more enjoyable or part-time work sooner.
Turns the vague idea of "saving enough early" into a single, trackable number.
Harnesses the full power of compounding by front-loading investments.
Reduces financial pressure — you only need to cover current expenses, not save on top.

Cons

Rests entirely on one long-run return assumption that markets may not deliver.
A prolonged downturn after you stop contributing can leave you short at retirement.
Uses today’s expenses and a nominal return, which can understate the real target.
Requires discipline not to spend the coasting corpus before retirement.

Tips

1Front-load investing in your 20s and 30s — every year of extra compounding shrinks the coast number.
2Use a conservative return (8–10%) to build a safety margin into your coast target.
3Recheck your progress yearly and resume contributions if returns lag your plan.
4Keep the coasting corpus fully invested and untouched — spending it defeats the strategy.
5Pair Coast FIRE with adequate health insurance so a medical shock can’t force early withdrawals.

Frequently asked questions

Everything you need to know about the Coast FIRE Calculator.

What is Coast FIRE?

Coast FIRE is the point at which you have invested enough that, without adding another rupee, ordinary compounding will grow your portfolio to your full FIRE number by retirement. You still work to cover current expenses, but your retirement saving is effectively done.

How is Coast FIRE different from regular FIRE?

Regular FIRE means your corpus is already large enough to live off today, so paid work is optional now. Coast FIRE is an earlier milestone: your corpus is not yet enough to retire on, but it will grow into a sufficient one by your target retirement age with no further contributions.

How is the Coast FIRE number calculated?

It is the present value of your FIRE target. Take the corpus you need at retirement (annual expenses ÷ withdrawal rate) and discount it back to today at your expected return over the years remaining — Coast FIRE number = FIRE target ÷ (1 + return)^years.

Why does starting age matter so much?

Compounding is exponential, so time is the biggest lever. Investing early gives money decades to multiply, which is why a 30-year-old needs a small coast number while a 45-year-old with the same goal needs several times more up front.

Can I really stop investing once I hit Coast FIRE?

In theory, yes — for retirement. Once your corpus reaches the coast number, growth alone should reach your FIRE target, so you only need income to cover current living costs. Many people instead keep investing to build a buffer against lower-than-expected returns or to retire even earlier.

What return assumption should I use?

Coast FIRE is very sensitive to the return you assume, because it is compounded over many years. A diversified equity-heavy portfolio has historically returned around 11–13% a year in India over long horizons, but a more conservative 8–10% builds in a margin of safety and raises the coast number you should aim for.

Does this account for inflation?

This calculator uses expenses in today’s money and a nominal return. Because both future expenses and the portfolio inflate, a common refinement is to enter a real (inflation-adjusted) return — expected return minus inflation — which produces a more conservative, larger coast number.

What is Barista FIRE and how does it relate?

Barista FIRE is a close cousin: you cover current expenses with part-time or lighter work while your invested corpus coasts toward the FIRE number. Reaching Coast FIRE is often what makes a Barista FIRE lifestyle financially safe.

What if my investments fall short of the coast number?

Then compounding alone will not reach your FIRE target, and the calculator shows the shortfall. You close it by investing more now, extending your retirement age (more compounding time), trimming expected expenses, or accepting a higher assumed return with its added risk.

Is Coast FIRE risky?

Its main risk is relying on a single return assumption over decades. A long stretch of below-average returns can leave you short, and you will have stopped contributing. Recheck your progress every year or two and be ready to resume investing if markets underperform your plan.

Methodology & sources

How the Coast FIRE Calculator is calculated, and where the underlying rules come from.

How we calculate it

Every result is produced by a single, shared and tested financial-formula library used across the whole site — so the maths is consistent from one calculator to the next. Figures are estimates based on the inputs you enter and standard assumptions (such as regular compounding and constant rates); real-world outcomes vary with taxes, fees and changing rates. All calculations run in your browser — nothing you type is stored or sent to a server.

Sources & references

Editorial policy & disclaimer. FinCalcHub provides free educational tools and estimates — not personalised financial, tax or investment advice. Verify important decisions with a qualified professional. Read our editorial approach, disclaimer and privacy policy.

Reviewed by Dhirendra Bisht, Founder & Lead Engineer, FinCalcHub — last reviewed 27 July 2026.

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