Compound Interest Calculator
Calculate compound interest on a principal amount with a configurable compounding frequency (annual, half-yearly, quarterly, or monthly), showing how more frequent compounding grows the final amount.
- 1Enter the principal amount
- 2Enter the annual interest rate
- 3Enter the number of years
- 4Enter the compounding frequency per year and click Calculate to see the final amount and interest
The formula
The calculator uses A = P × (1 + r/n)^(n×t), where P is the principal, r the annual rate as a decimal, n the number of compounding periods per year and t the years. It reports the final amount and the interest, which is A − P.
Choosing the compounding frequency
- 1 = yearly, 2 = half-yearly, 4 = quarterly, 12 = monthly, 365 = daily.
- More frequent compounding gives a slightly higher result. Rs. 1,00,000 at 8% for 10 years is about Rs. 2,15,892 compounded yearly and about Rs. 2,21,964 compounded monthly.
Good to know
- This is a one-time deposit with no further contributions. For regular monthly investing use the SIP calculator.
- The rate is assumed constant. Real savings and loan rates change over time.
- Inflation and tax are ignored, so the figure is a nominal amount, not what the money will buy.
The rule of 72
A quick check: dividing 72 by the annual rate gives the approximate years to double your money. At 8% that is about 9 years, which matches the calculator (the amount is about 2.16 times the principal after 10 years).
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