Early Retirement Calculator - How Much Corpus Do You Need?

Understanding Your Retirement Number

The most common question about early retirement is: "How much money do I need?" The honest answer is that it depends on your lifestyle, inflation expectations, and life expectancy — but "it depends" isn't useful on its own, so this guide walks through the actual framework for turning your monthly expenses today into a single target corpus number you can plan against.

The 4% Rule — Explained Simply

The 4% rule says you can withdraw 4% of your corpus in the first year of retirement, and adjust that withdrawal amount for inflation each year after, without running out of money for 30+ years. It traces back to a 1994 study by financial planner William Bengen, later expanded into the widely-cited 1998 "Trinity Study" (origin of the 4% rule) — both analyzed historical US market returns, not Indian ones. It's a starting heuristic, not a guarantee, which is why many early retirees in India use a more conservative 3-3.5% instead, especially given that Indian inflation and market data have a shorter track record than the US markets the original rule was based on.

Your target corpus = Annual expenses ÷ 4% (or × 25)

The reason this formula works is really just algebra flipped around: if 4% of your corpus covers a year of expenses, then your annual expenses times 25 gives you the corpus that 4% equals. Using 3.5% instead (multiplying by roughly 28-29) builds in more of a safety margin, at the cost of needing a larger corpus before you can retire.

Inflation-Adjusted Corpus Calculator

Use this framework to calculate your number:

Step 1: Estimate Current Annual Expenses

Monthly expenses: ₹______ × 12 = ₹______ (Annual)
Add buffer for healthcare: + 20%
Adjusted annual expense: ₹______

Be honest here, not aspirational — most people underestimate their real monthly spending by leaving out annual or irregular costs (insurance premiums, festival spending, home maintenance, gifts) that don't show up in a typical month but absolutely show up over a year. Pull actual numbers from your bank statements over the last 6-12 months rather than guessing; this single step is where most early-retirement corpus estimates go wrong before the math even starts.

Step 2: Project Future Expenses

With 6% inflation, expenses roughly double every 12 years — a useful mental shortcut when you don't want to do the compound-interest math by hand.

This is the step people most often skip, and it's the most expensive one to skip. Planning for early retirement using today's expense number, without inflating it forward to the year you'll actually retire, is one of the most common reasons FIRE plans fall short — you end up with a corpus sized for today's cost of living arriving 15-20 years too early.

Step 3: Calculate Your Corpus

Notice the gap between the two columns widens as expenses grow — the more you spend, the more that extra 0.5% margin of safety costs you in corpus terms. Which rule to use isn't purely a math question either: someone retiring at 45 with a 45-year runway ahead of them generally has more reason to lean conservative (3.5% or lower) than someone with a shorter post-retirement horizon.

Sample Scenarios

Scenario A: Aggressive (Age 30, Retire at 45)

• Current monthly expenses: ₹40,000
• Expenses at retirement (15 years, 6% inflation): ₹95,000/month
• Annual expenses: ₹11,40,000
• Corpus needed (4% rule): ₹2.85 Cr
• Monthly SIP needed (12% returns): ₹56,500

Scenario B: Moderate (Age 28, Retire at 50)

• Current monthly expenses: ₹30,000
• Expenses at retirement (22 years, 6% inflation): ₹1,08,000/month
• Annual expenses: ₹12,96,000
• Corpus needed (4% rule): ₹3.24 Cr
• Monthly SIP needed (12% returns): ₹25,000

The difference between these two scenarios isn't really about age — it's about the retirement timeline. Scenario A compresses the same order-of-magnitude corpus into 15 years instead of 22, which is why its required SIP is more than double, even though its target corpus is smaller. If a monthly SIP number looks unaffordable, extending your target retirement age by even 3-5 years often brings it down substantially, since you gain both extra contribution years and extra compounding years at once.

Key Adjustments for India

1. Medical inflation: Add 12-14% annually for health insurance premiums — recent industry surveys put Indian medical inflation at 12-14% versus general CPI inflation of around 4-5% (medical inflation estimates, DSIJ), and this gap tends to widen as you age and your policy's premiums rise with it.
2. Children's education: Keep separate investments, don't dip into retirement corpus — education costs (especially for higher studies or study abroad) arrive on their own timeline, often before retirement, and raiding your retirement number to cover them undoes years of compounding at exactly the wrong time.
3. Housing: Own your home before retirement to reduce expenses — a paid-off home removes your single largest fixed monthly cost from the "annual expenses" figure that drives your entire corpus calculation, which is why most FIRE plans in India explicitly target mortgage-free status before the retirement date.
4. Unexpected expenses: Keep 5% of corpus as contingency buffer for the genuinely unplannable — a major repair, a family emergency, a gap year in the market right when you need to withdraw.

Use Saferaho's Retirement Calculator

For a personalized calculation tailored to your specific situation, use our free Retirement Corpus Calculator or speak with a Saferaho advisor who can help you model different scenarios, stress-test your number against a market downturn in your first retirement years, and decide between the 4% and 3.5% approach based on your actual timeline.

Summary

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Related Reading

• Best Early Retirement Investment Plans in India 2026
• Best SIP Strategy for Early Retirement Corpus Building
• How to Retire Early in India - Complete FIRE Guide
• Browse the full Early Retirement guide
• Plan your numbers with our free Retirement Corpus Calculator