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6 min readUpdated July 2026

Understanding Real Rate of Return: How Inflation Changes Your Net Investment Gains

Learn how inflation erodes purchasing power, how to calculate real rate of return using the Fisher equation, and how to protect long-term financial goals.

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Nominal vs. Real Rate of Return

Nominal return is the raw percentage increase in your money over time, while real rate of return adjusts that gain for inflation to show true growth in purchasing power.

If your fixed deposit or bond yields 7% per year but general inflation runs at 6%, your real return is only around 0.94% post-inflation. Ignoring inflation leads to severe underfunding of long-term goals like retirement.

The Exact Mathematical Formula (Fisher Equation)

While subtracting inflation from nominal return (7% - 6% = 1%) is a popular shortcut, the mathematically exact real rate of return uses the Fisher Equation:

Real Return = [(1 + Nominal Rate) / (1 + Inflation Rate)] - 1. For a 7% return and 6% inflation, (1.07 / 1.06) - 1 equals 0.943%.

Beating Inflation with Growth Assets

Traditional savings accounts and low-yield fixed deposits often fail to deliver a positive real return after accounting for both inflation and income tax slabs.

To preserve and compound purchasing power, portfolios require an allocation to inflation-beating asset classes such as diversified equities, equity mutual funds, or inflation-indexed instruments.

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FAQs

Why is my purchasing power lower even when my bank account grows?

Because the price of goods and services (inflation) increases faster than the interest rate paid on your bank account.

What inflation rate should I assume for retirement planning?

Financial planners usually recommend assuming a 6% to 7% annual inflation rate for general expenses, and 8% to 10% for healthcare and education expenses.

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