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Compound Interest Calculator

Calculate compound interest with monthly contributions, multiple compounding frequencies, and year-by-year breakdown.

Total Value After 10 Years
₹26,53,429
₹13,00,000
Total Deposited
₹13,53,429
Interest Earned
104.1%
Total Return
Deposited (49.0%)Interest (51.0%)

Growth Over Time

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DepositedInterest

Compound Interest Formula

A = P(1 + r/n)^(nt)

  • A = Final amount
  • P = Principal (initial investment) = ₹1,00,000
  • r = Annual interest rate = 12%
  • n = Compounding frequency = 12x/year
  • t = Time in years = 10

With monthly contributions of ₹10,000, the formula is extended to include the future value of an annuity component, resulting in significantly higher returns due to regular investing.

About Compound Interest Calculator

Free compound interest calculator that shows how your investments grow over time with the power of compounding. Enter your initial principal, annual interest rate, investment period, and optional monthly contributions. Choose from five compounding frequencies — annually, semi-annually, quarterly, monthly, or daily. See your total returns with a visual growth chart, principal vs interest breakdown bar, and a detailed year-by-year table showing opening balance, deposits, interest earned, and closing balance for each year. The tool also displays the compound interest formula with your actual values. Perfect for planning savings goals, comparing investment options, understanding FD returns, or projecting retirement corpus. All calculations run in your browser — completely free and private.

Frequently Asked Questions

What is compound interest?
Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods. Unlike simple interest (which only earns on the principal), compound interest makes your money grow exponentially over time. This is why it's called 'interest on interest' — the longer you invest, the faster your wealth grows.
How does compounding frequency affect returns?
The more frequently interest is compounded, the higher your returns. For example, ₹1,00,000 at 12% for 10 years yields: ₹3,10,585 (annually), ₹3,20,714 (semi-annually), ₹3,26,204 (quarterly), ₹3,30,039 (monthly), and ₹3,31,946 (daily). Monthly or quarterly compounding is most common for bank deposits in India.
What is the compound interest formula?
The formula is A = P(1 + r/n)^(nt), where A = final amount, P = principal, r = annual interest rate (as decimal), n = number of compounding periods per year, and t = time in years. With monthly contributions, an additional future value of annuity component is added: FV = PMT × [((1 + r/n)^(nt) - 1) / (r/n)].
How are monthly contributions calculated?
Monthly contributions are added at the start of each compounding period. For monthly compounding, each contribution starts earning compound interest immediately. Over long periods, regular monthly contributions can significantly outperform a one-time lump sum investment due to rupee cost averaging and continuous compounding.
What is the Rule of 72?
The Rule of 72 is a quick way to estimate how long it takes to double your money. Divide 72 by the annual interest rate — the result is the approximate number of years to double. For example, at 12% returns, your money doubles in about 72/12 = 6 years. At 8%, it takes about 9 years.
Is this calculator accurate for Indian investments?
Yes. The calculator uses standard compound interest mathematics and displays results in Indian Rupee (INR) format with the Indian numbering system (lakhs, crores). It's suitable for calculating returns on FDs, RDs, mutual funds, PPF, and other investments. Note that actual returns may vary due to taxes, fees, and fluctuating interest rates.