Investing
Compound Interest Calculator
See the magic of interest earning interest, year after year.
₹1,00,000
10%
10 yr
Principal37%
Interest63%
Principal₹1.00 L
Interest₹1.69 L
Maturity₹2.69 L
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Compound interest is interest earned on both your principal and the interest already accumulated — the single most powerful force in personal finance. This calculator shows how any principal grows over time so you can appreciate why starting early matters so much.
How this calculator works
Enter your principal, the annual interest rate, and the number of years. The calculator applies quarterly compounding and shows your principal, total interest earned and final maturity amount.
The formula
A = P × (1 + r/m)^(m × n)- A
- = Final amount
- P
- = Principal
- r
- = Annual rate (as a decimal)
- m
- = Compounding frequency per year (4 = quarterly)
- n
- = Number of years
The more frequent the compounding, the more you earn. This calculator uses quarterly compounding by default.
Worked example
Example: ₹1,00,000 at 10% for 10 years
Principal₹1,00,000
Rate10% p.a.
Years10
Grows to about ₹2.68 lakh — roughly ₹1.68 lakh earned purely from compounding.
Key benefits
- Illustrates why time in the market beats timing the market
- Universal formula behind FDs, bonds and reinvested returns
- Shows the cost of starting late
- Helps set realistic long-term expectations
Smart tips
- Start early — a few extra years dramatically changes the outcome
- Reinvest interest/dividends to keep compounding
- Higher compounding frequency helps, but rate and time matter more
- Beware compounding working against you on high-interest debt
Frequently asked questions
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Explore all free financial calculators. Results are indicative estimates for information only and not investment, tax or legal advice.