Worked example
Example with the default numbers — change them above.
Your age today: 32 · Age you want to retire: 50 · Monthly spending today: ₹1,00,000 · Fat FIRE monthly budget (today's money): ₹1,50,000 · Investments today: ₹75,00,000 · Monthly saving and investing: ₹1,50,000 · Assumed return per year: 11% · Inflation per year: 6% · Withdrawal rate in retirement: 3.5%
On a Fat FIRE budget of ₹1,50,000 a month, your Fat FIRE number is ₹5.14 Cr in today's money (₹14.68 Cr by age 50). Investing ₹1,50,000 a month, you reach it in 14 yrs 2 mo (age 46), 3 yrs 10 mo before your target age of 50.
| You reach Fat FIRE | Age 46 · In 14 yrs 2 mo |
|---|---|
| Fat FIRE number at 50 | ₹14.68 Cr · ₹5.14 Cr in today's money, 28.6× yearly spending |
| Gap at age 50 | On track · Projected investments ₹19.98 Cr, ₹5.3 Cr to spare |
| Monthly saving to retire at 50 | On track · ₹97,257 a month would already be enough |
| Monthly spending at 50 | ₹4,28,151 · Today's ₹1,50,000 after 6% inflation |
| Compared with regular FIRE | 4 yrs 4 mo later · Regular FIRE number ₹3.43 Cr in today's money |
How the Fat FIRE Calculator works
- Your Fat FIRE monthly budget, in today's rupees, is inflated to each future year at your inflation rate.
- The Fat FIRE number is that yearly budget divided by your withdrawal rate.
- Your investments grow monthly with your saving, raised once a year, at your expected return.
- The age you reach Fat FIRE is the first month your investments meet the rising target.
- The same steps run for your current spending, so you can see how many extra working years the bigger budget costs.
Fat FIRE number
Fat FIRE number at age A = 12 × B × (1 + i)^(A − current age) ÷ w
B = Fat FIRE monthly budget in today's money
i = inflation; w = withdrawal rate
Regular FIRE uses today's spending S in place of BAssumptions and limits
- The 1.5× default for the Fat FIRE budget is a site convention for illustration, not a standard definition.
- Returns are the same every year; real markets rise and fall.
- Spending rises with the inflation you enter; some Fat FIRE costs, such as foreign travel or private healthcare, can rise faster.
- Large one-off goals such as a second home or children's overseas education are not included; plan them separately.
- Tax is not modelled; enter returns after costs.
Frequently asked questions
What is Fat FIRE in India and how much do I need?
Fat FIRE is early retirement on a generous budget with room to spare. There is no official threshold; people define it by lifestyle. The corpus is your yearly budget divided by your withdrawal rate, so ₹2 lakh a month at 3.5% needs about ₹6.9 crore in today's money. Inflate that to your retirement year and the rupee figure grows much larger.
How long does Fat FIRE take compared with regular FIRE?
Longer, because the target grows in step with the budget: a 50% bigger budget means a 50% bigger corpus. How many extra years that costs depends on how much you save and how long compounding has to work. The comparison on this page shows the years for both budgets on your actual saving plan, which is usually the clearest way to decide.
Is a 3.5% withdrawal rate right for Fat FIRE?
It is a common starting point, but over 45 years it succeeds in only about 7 of 10 of the Monte Carlo simulator's default futures. A Fat FIRE budget has more discretionary spending, such as travel, that can be cut in bad years, which gives some flexibility a lean budget lacks. Some people use that flexibility to justify a slightly higher rate; others keep the margin. Test your choice in the FIRE Monte Carlo simulator.
What should a Fat FIRE budget include?
Everything you expect to spend for decades, not just today's bills: regular travel, a car replacement cycle, home maintenance, support for parents or adult children, hobbies and gifts. Healthcare deserves its own line, including insurance premiums that rise with age. Big one-off goals, like a child's overseas education, are better planned as separate goals than folded into the monthly figure.
Does Fat FIRE need a different investment mix?
Not necessarily. The mix depends on how much risk you can live with and how long the money must last, not on the size of the budget. A bigger corpus can make it easier to hold several years of spending in debt or deposits as a buffer. This calculator uses one expected return; the Monte Carlo simulator lets you test different equity, debt and gold mixes.
How do I stop Fat FIRE becoming a moving target?
Write down the budget and the number before you get close, and agree on it with your family. Many people keep raising the bar as their income rises and never feel ready. Revisit the budget once a year with actual spending data rather than guesses, and decide in advance what would make you comfortable enough to stop full-time work.
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 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?
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Retirement & FIRE Retirement Corpus Calculator
How much money do I need when I retire?
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