I asked ChatGPT to calculate how inflation affects growth of my ₹50 lakh investment—the answer was a wake-up call

I asked AI can inflation reduce the gains from compounding? Here's what it says

I asked ChatGPT I want to understand the impact of inflation on the long-term growth of my investment corpus. Assume I invest ₹50 lakh as a lump sum today in a diversified equity mutual fund and hold it for 20 years.

What is compounding?

Compounding is the process where your investment earns returns, and then those returns start earning returns themselves.

For example:

• You invest ₹100.
• It grows by 10% in Year 1 → ₹110.
• In Year 2, you earn 10% on ₹110, not ₹100.
• Value becomes ₹121.

The extra ₹1 earned in Year 2 (beyond ₹120) comes from earning returns on previous returns.

This is why compounding is often called "interest on interest" or "returns on returns."

How compounding grows wealth over long periods

Compounding works slowly at first and then accelerates.

The formula is:

FV=PV(1+r)n

Where: FV = Future Value, PV = ₹50,00,000, r = 12% = 0.12, n = 20 years

For a ₹50 lakh investment:

• At 10%, it becomes about ₹1.30 crore in 10 years.
• But in the next 10 years, it grows from ₹1.30 crore to ₹3.36 crore.

The second decade creates much more wealth than the first because compounding has a larger base to work on.

Why inflation reduces purchasing power

Inflation means prices rise over time.

Suppose:

• A basket of goods costs ₹100 today.
• Inflation is 6%.
• After 20 years:
• ₹100 worth of goods will cost roughly ₹321.

So even if your investment grows, the amount of goods and services it can buy may not grow at the same pace.

How inflation affects the benefits of compounding

Compounding grows your money.

Inflation reduces what that money can buy.

Therefore, investors should focus not only on:

Nominal Return = Investment Return

but also:

Real Return = Return after adjusting for inflation

Approximation:

Real Return≈1+i/1+r​−1

Where: r = investment return, i = inflation rate

The higher the inflation rate, the lower the real wealth created.

₹50 Lakh Lump Sum Invested for 20 Years

Future Value Formula

FV = ₹50,00,000 × (1 + Return)^20

Key Takeaways

Scenario 1: 10% return, 6% inflation

Initial investment: ₹50 lakh

Nominal corpus after 20 years: ₹3.36 crore

Inflation-adjusted value: ₹1.05 crore

While the statement shows ₹3.36 crore, its purchasing power is equivalent to only about ₹1.05 crore in today's money.

Scenario 2: 12% return, 6% inflation

Nominal corpus: ₹4.82 crore

Real corpus: ₹1.50 crore

Despite earning a strong equity-like return, inflation erodes nearly ₹3.3 crore of apparent gains.

Scenario 3: 15% return, 6% inflation

Nominal corpus: ₹8.18 crore

Real corpus: ₹2.56 crore

This demonstrates why higher-return assets such as diversified equity funds have historically been among the best tools for beating inflation over long periods.

The Big Lesson

Compounding and inflation are constantly competing:

• Compounding pushes wealth upward.
• Inflation pulls purchasing power downward.

The wealth that truly matters is not the corpus shown in your account statement but the inflation-adjusted corpus.

For a long-term investor, the goal is therefore not simply to earn 10–12% returns, but to generate a healthy real return (return minus inflation). Even a seemingly small difference of 2–3 percentage points in real return can translate into crores of additional purchasing power over a 20-year period.