Compounding happens when returns are added to an original amount and future returns are then earned on the growing total. Over enough time, that “return on return” changes the shape of the outcome from a straight line into a curve.
It is a mathematical mechanism, not an investment product — and certainly not a guarantee. Its effect depends entirely on the contributions, rate, timing, costs, and real-world returns involved.
THE CENTRAL IDEA
Time does not guarantee a good outcome. But when returns are positive and reinvested, more time gives compounding more opportunities to work.
Try the mathematics
Change an input. See the curve respond.
This educational calculator uses a constant annual rate. Real investment returns do not arrive smoothly.
INTERACTIVE ILLUSTRATIONAdjust the assumptions
Assumes contributions are made at the end of each year and returns compound annually.
ILLUSTRATIVE FUTURE VALUE–
Total contributions–
Illustrative growth–
Illustrative valueContributions
Illustration, not a forecast. Actual returns are variable and not guaranteed. Fees, taxes, inflation, and periods of loss are not included.
Aarav and Diya
Aarav invests ₹10,000 annually for 30 years. Diya invests ₹20,000 annually for 15 years. Both contribute ₹3,00,000 in total.
AARAV · 30 YEARS₹16.45 lakhIllustrative future value
DIYA · 15 YEARS₹6.35 lakhIllustrative future value
Assuming a constant 10% annual return compounded annually, with contributions made at the end of each year. Rounded approximate values.
Read the caveat
What compounding doesn’t promise.
A neat upward curve is useful for understanding the mathematics. It is not a picture of how markets behave.
Returns are not constant +
Real returns vary from year to year and can be negative. The sequence of those returns can matter.
Inflation changes purchasing power +
A future rupee may buy less than a rupee today. Nominal figures do not show this effect.
Costs and taxes matter +
Fees and taxes can reduce the amount left to compound and are excluded from this illustration.
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Compounding worksheet
A one-page worksheet with the article's worked example — Aarav and Diya side by side — plus space to run your own numbers.
