Retirement PlanningApril 13, 2026·12 min read

How to Calculate Your Retirement Corpus: The Inflation-Adjusted Formula

Most Indians plan for retirement using a number they heard somewhere — ₹1 crore, ₹2 crore. These are not plans. Your retirement corpus number must come from your actual expenses, your retirement age, life expectancy, inflation, and healthcare costs. This is how to calculate it.

Section 01

Why ₹1 Crore Is Not Enough for Retirement in India

A common retirement target in Indian personal finance circles is ₹1 crore. This number is meaningless without context — and in most cases, deeply inadequate.

₹1 crore today

₹1,00,00,000

Sounds like a lot. At 4% withdrawal rate, generates ₹33,333/month.

After 6% inflation, 20 years

₹32 lakh equivalent

₹1 crore today has the purchasing power of ₹32 lakh in 2046. Your corpus must account for this.

What ₹50K/month needs in 2046

₹1.6 lakh/month

If you need ₹50,000/month today, you will need ₹1.6 lakh/month in 2046 for the same lifestyle at 6% inflation.

The real problem — Most people think in nominal terms — ₹1 crore sounds big today. But retirement planning is about future purchasing power, not absolute numbers. Your corpus target must be calculated in future rupees, not today's rupees.

Section 02

The 4-Step Corpus Calculation Formula

This is the calculation every Indian investor should do at least once. It requires four inputs: current monthly expenses, years to retirement, expected years in retirement, and inflation rate.

Calculate your current monthly expenses

List all current monthly expenses — rent/EMI, utilities, groceries, transport, entertainment, insurance premiums. Exclude child education and loans that will end before retirement. This is your today-rupee baseline.

Current monthly expense = ₹X

Example: ₹60,000/month

Inflate to retirement date

Multiply by inflation factor for years until retirement. At 6% inflation, the factor is (1.06)^n where n = years to retirement.

Future monthly expense = X × (1 + inflation)^years

₹60,000 × (1.06)^25 = ₹60,000 × 4.29 = ₹2,57,400/month

Apply the 300x multiplier (25x annual rule)

Multiply the future monthly expense by 300 (= 25 years × 12 months). This gives the corpus needed assuming a 4% withdrawal rate on a balanced portfolio. For 30 years, use 360. For 35 years, use 420.

Corpus = Future monthly expense × 300

₹2,57,400 × 300 = ₹7.7 crore

Add healthcare corpus separately

Healthcare costs in India inflate at 10–14% annually. Budget ₹50–75 lakh as a separate healthcare corpus (in a conservative fund, not equity). This is not counted in the living-expenses corpus.

Total target = Living corpus + Healthcare corpus

₹7.7 crore + ₹75 lakh = ₹8.45 crore total

Section 03

Corpus Reference Table: How Much You Need by Age and Expense Level

The table below shows the retirement corpus required at different current monthly expense levels, assuming 6% inflation, retirement at 60, life expectancy 85 (25 years in retirement), and the 4% withdrawal rate (300x multiplier).

Current expense	Retire in 10yr	Retire in 20yr	Retire in 30yr
₹30,000/month	₹1.6 Cr	₹2.9 Cr	₹5.2 Cr
₹50,000/month	₹2.7 Cr	₹4.8 Cr	₹8.6 Cr
₹75,000/month	₹4.0 Cr	₹7.2 Cr	₹12.9 Cr
₹1,00,000/month	₹5.4 Cr	₹9.7 Cr	₹17.3 Cr
₹1,50,000/month	₹8.1 Cr	₹14.5 Cr	₹25.9 Cr

These numbers assume expenses are fully funded from the corpus (no other income). If you have pension, rental income, or a working spouse, reduce the corpus target accordingly. Each ₹10,000/month of other income reduces the required corpus by ~₹30 lakh.

Section 04

How Much SIP Do You Need to Hit Your Corpus Target?

Once you know your corpus target, the next question is: what monthly SIP amount gets you there? The formula uses the future value of an annuity at the assumed return rate.

Monthly SIP needed for ₹5 crore corpus at 12% CAGR

10 years₹2,30,000/monthExtremely aggressive — only for high earners with no commitments

15 years₹90,000/monthAchievable for upper-middle income households

20 years₹38,000/monthComfortable for most dual-income households

25 years₹17,000/monthAccessible for most salaried professionals starting early

30 years₹8,000/monthThe compounding miracle — start at 25, retire at 55 with ₹5Cr

The time value of starting early — A 25-year-old starting ₹8,000/month reaches ₹5 crore by age 55 (30 years at 12%). A 35-year-old needs ₹38,000/month to reach the same target by 55 (20 years). Same goal. Same fund. 4.75x more monthly commitment for starting 10 years later.

Section 05

5 Variables That Radically Change Your Corpus Number

Small changes in assumptions have enormous compounding effects over 20–30 years. Understanding the sensitivity of your corpus calculation helps you make better planning decisions.

Inflation rate assumption

Conservative: 5% inflation (optimistic)Aggressive: 7% inflation (pessimistic)

For a 25-year horizon, the difference in required corpus is 40–50%. At 7% inflation, ₹50,000/month today becomes ₹2.7 lakh/month in 25 years vs ₹1.7 lakh at 5%.

Return rate assumption on corpus

Conservative: 7% return (conservative, debt-heavy)Aggressive: 10% return (equity-heavy balanced fund)

At 7% return, you need a 7% withdrawal rate to generate the same income — which depletes corpus. At 10%, the 4% withdrawal rate is sustainably within margin.

Life expectancy

Conservative: 75 years (15 years post-retirement)Aggressive: 90 years (30 years post-retirement)

Planning for 90 instead of 75 requires 2x the corpus. With increasing Indian longevity, planning to 85–90 is prudent — especially for women who statistically outlive men by 5–7 years.

Other income in retirement

Conservative: Zero pension / rental incomeAggressive: ₹30,000/month from pension or rent

₹30,000/month of other income reduces required corpus by ~₹90 lakh at the 4% withdrawal rate. Don't build a ₹7 crore plan if you have a ₹30,000/month pension.

Expense reduction at retirement

Conservative: Same expenses as working yearsAggressive: 30% expense reduction at retirement

Post-retirement, many costs fall: EMIs end, commuting stops, professional expenses disappear, children are financially independent. A realistic 20–30% expense reduction meaningfully lowers the corpus target.

Section 06

The Healthcare Corpus: The Variable Most People Ignore

Healthcare is the largest wildcard in Indian retirement planning. Medical inflation in India runs at 10–14% annually — nearly double the general inflation rate. A hospitalisation that costs ₹2 lakh today will cost ₹5–8 lakh in 2040.

Healthcare cost escalation at 12% medical inflation

Procedure	Cost today (2026)	Cost in 2036	Cost in 2046
Cardiac bypass surgery	₹2.5 lakh	₹7.8 lakh	₹24 lakh
Knee replacement	₹1.8 lakh	₹5.6 lakh	₹17 lakh
Cancer treatment (basic)	₹5 lakh	₹15.5 lakh	₹48 lakh
Annual health check (couple)	₹15,000	₹46,000	₹1.4 lakh

Healthcare corpus sizing

Single, no dependants: ₹40–50 lakh
Couple, healthy at 60: ₹60–75 lakh
Couple, existing conditions: ₹1–1.5 crore
Keep separate from living corpus — don't touch unless needed

Health insurance is not optional

Buy ₹25–50 lakh family floater policy before age 60
Get super top-up cover (₹50L–1Cr at low premium)
Healthcare corpus covers what insurance doesn't
Never cancel health insurance to fund retirement living

Section 07

The Retirement Age Multiplier Effect

Retirement age has a double impact: every year you delay retirement, you save one more year of SIP and shorten the period your corpus needs to last. This is the most powerful lever in retirement planning.

Impact of retiring at 55 vs 60 vs 65 — ₹50K/month current expenses

Retire at 55 (30 years to build, 30 years in retirement)

Target corpus: ₹8.6 croreSIP required: ₹8,000/month (starting at 25) or ₹38,000/month (starting at 35)

Retire at 60 (35 years to build, 25 years in retirement)

Target corpus: ₹7.7 croreSIP required: ₹4,500/month (starting at 25) or ₹24,000/month (starting at 35)

Retire at 65 (40 years to build, 20 years in retirement)

Target corpus: ₹6.5 croreSIP required: ₹2,800/month (starting at 25) or ₹15,000/month (starting at 35)

Section 08

What Depletes a Retirement Corpus — 4 Warning Scenarios

Scenario 1: Withdrawal rate too high

At 7% withdrawal on a corpus earning 8%, the net growth is 1%. At 6% inflation, real corpus declines 5% per year. A ₹2 crore corpus becomes ₹80 lakh in real terms after 20 years.

Fix: Keep withdrawal rate below 5% of corpus. At 12% return, 4% withdrawal grows the corpus.

Scenario 2: Sequence-of-returns risk in early retirement

Markets fall 40% in years 1–2 of retirement. You sell units at low prices. Even if markets fully recover, the depleted unit count means you never fully recover the corpus.

Fix: Bucket strategy — draw from liquid/debt bucket in first 2 years, give equity time to recover.

Scenario 3: No inflation adjustment on withdrawals

A fixed ₹30,000/month withdrawal in 2026 buys less than half as much in 2046 at 6% inflation. The corpus may survive but real lifestyle quality declines sharply.

Fix: Build in 5% annual step-up on SWP from year 5 onward. Corpus must earn enough to support this.

Scenario 4: Major unplanned healthcare expense

A single cardiac event or cancer diagnosis without adequate insurance can require ₹10–50 lakh in one year. Without a separate healthcare corpus, this comes from the living expenses corpus.

Fix: Separate healthcare corpus + super top-up health insurance. Never let a medical event touch your living corpus.

Section 09

Tracking Progress: Are You On Track for Your Corpus Target?

Calculating the target corpus is step one. Tracking whether your current savings are on the path to hit it is equally important — and rarely done.

Annual retirement readiness check

What is your current investable corpus (mutual funds + EPF + PPF + other investments)?

Sum all retirement-earmarked investments at current value

What should your corpus be at this age to be on track?

Use a retirement calculator to compute the 'milestone corpus' for your age

Are you ahead, behind, or on track?

If behind by >20%, increase SIP amount. If ahead, maintain course.

Has your monthly expense level changed significantly?

Recalculate the corpus target with updated expenses annually

Have you accounted for any expected windfall or corpus boost?

Inheritance, property sale, ESOPs — factor into total retirement corpus

Section 10

Your Retirement Corpus Action Plan: Do This This Weekend

Retirement planning is not a one-time calculation — but it requires a first calculation. Here is what to do in the next 48 hours.

List your current monthly expenses across all categories. This takes 20 minutes with your bank statement.

Decide your target retirement age. Be honest — factor in health, career trajectory, and desire to stop working.

Calculate inflation-adjusted future monthly expense: today's expense × (1.06)^years to retirement.

Multiply future monthly expense × 300 to get your living corpus target.

Add ₹50–75 lakh separately for healthcare corpus.

Check your current investable corpus (EPF + mutual funds + other). Is it on track?

Calculate the monthly SIP needed to bridge the gap from current corpus to target. Use a SIP calculator.

Set up or increase SIP to that amount this week — not next month.

Frequently Asked Questions

How much corpus do I need to retire in India?

The amount depends on your current monthly expenses, your retirement age, life expectancy, and inflation. A common starting point: multiply your expected monthly expenses at retirement by 300 (25x annual expenses). For someone spending ₹1 lakh/month in today's money, that is a ₹3 crore corpus in today's terms. After inflating at 6% for 20–25 years, this becomes ₹9–16 crore target corpus.

What is the 25x rule for retirement corpus?

The 25x rule says your retirement corpus should be 25 times your annual expenses at retirement. This is derived from the 4% safe withdrawal rate — a corpus 25x your annual expenses allows you to withdraw 4% per year indefinitely (assuming a balanced portfolio averaging 7–8% real returns). For Indian investors with higher inflation, consider 28–30x as a more conservative target.

How does inflation affect retirement corpus calculation in India?

Indian inflation averages 6% annually. At 6% inflation, your purchasing power halves every 12 years. If you need ₹50,000/month today, you will need ₹89,000/month in 10 years and ₹1,60,000/month in 20 years for the same lifestyle. Your corpus calculation must use the inflation-adjusted future value of your expenses — not today's expenses.

How much SIP do I need to build a ₹5 crore retirement corpus?

At 12% CAGR: 20 years requires ₹49,000/month SIP; 25 years requires ₹24,000/month; 30 years requires ₹12,000/month. The difference between starting at 25 vs 35 is dramatic — a 10-year head start cuts the required monthly SIP by more than half. Time in market is the single biggest variable in retirement corpus accumulation.

Should I include healthcare costs in my retirement corpus calculation?

Yes — and most Indian investors significantly underestimate this. Healthcare inflation in India runs at 10–14% annually, far above CPI. A couple aged 60 may need ₹5–15 lakh/year in healthcare by age 70–80. Separately budgeting ₹50–75 lakh as a dedicated healthcare corpus (in a liquid to short-duration fund) is prudent in addition to the living-expenses corpus.

What is the difference between retirement corpus and retirement income?

Retirement corpus is the total accumulated wealth. Retirement income is what that corpus generates each month — via SWP, FD interest, rental income, or pension. The corpus must be large enough that the sustainable withdrawal rate (3.5–5% annually) covers your monthly income need. At 4% withdrawal on ₹2 crore, monthly income is ₹66,666 — before tax.

Retirement Planning

Systematic Withdrawal Plan (SWP): Tax-Efficient Retirement Income from Mutual Funds

Once you have the corpus, SWP is how you turn it into monthly income — more efficiently than FD or annuity.

SIP Planning

Why Most SIP Portfolios Fail: 10 Planning Gaps Every Indian Investor Must Fix

Consistency alone isn't a plan. Inflation, glide paths, and sequence risk are the gaps most investors miss.