Compound Interest Calculator

Calculate compound interest with different compounding frequencies

Details

Enter details and click Calculate

Maturity Amount

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Principal

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Interest Earned

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How to Use

  1. Principal โ€” enter the initial investment amount.
  2. Rate of Interest โ€” enter the annual interest rate.
  3. Time Period โ€” enter the investment duration in years.
  4. Compounding Frequency โ€” choose daily, monthly, quarterly, half-yearly, or annually.
  5. View Results โ€” see final amount, compound interest earned, and comparison with simple interest.

What is Compound Interest?

Compound interest is interest calculated on both the initial principal and the interest already accumulated. Unlike simple interest (which is calculated only on the principal), compound interest causes your money to grow exponentially โ€” the longer you invest, the faster it grows.

Compound Interest Formula

A = P ร— (1 + r/n)^(nร—t)

  • A = Final amount
  • P = Principal (initial investment)
  • r = Annual interest rate (as decimal)
  • n = Number of times interest is compounded per year
  • t = Time in years

Compound Interest = A โ€“ P

Simple Interest vs. Compound Interest

FeatureSimple InterestCompound Interest
FormulaP ร— r ร— tP ร— (1 + r/n)^(nt) โ€“ P
Growth patternLinearExponential
Where usedShort-term loansFDs, savings, mutual funds
โ‚น1L at 8% for 10 yearsโ‚น80,000 interestโ‚น1,15,892 interest (quarterly)

The Power of Compounding โ€” Why Frequency Matters

โ‚น1,00,000 at 10% p.a. for 5 years:

  • Simple interest: โ‚น50,000
  • Annually compounded: โ‚น61,051
  • Quarterly compounded: โ‚น63,862
  • Monthly compounded: โ‚น64,534
  • Daily compounded: โ‚น64,816

The difference between annual and daily compounding may seem small (โ‚น3,765 on โ‚น1L), but over 20โ€“30 years on larger amounts, frequent compounding compounds the difference dramatically.

Einstein's "Eighth Wonder"

Compound interest is famously attributed to Einstein as the "eighth wonder of the world." The Rule of 72 gives an intuitive feel: divide 72 by the annual interest rate to get the approximate number of years needed to double your money. At 8%, money doubles in 72/8 = 9 years. At 12%, it doubles in 6 years.