Compound Interest Calculator
Compound Interest Breakdown
⚠️ This calculator assumes a fixed interest rate throughout the tenure. Actual returns from investments may vary. Consult a financial advisor for investment decisions.
Impact of Compounding Frequency
| Frequency | Rs.1 Lakh @ 10% for 10 Years | Total Interest |
|---|---|---|
| Annually | Rs. 2,59,374 | Rs. 1,59,374 |
| Semi-annually | Rs. 2,65,330 | Rs. 1,65,330 |
| Quarterly | Rs. 2,68,506 | Rs. 1,68,506 |
| Monthly | Rs. 2,70,704 | Rs. 1,70,704 |
| Daily | Rs. 2,71,791 | Rs. 1,71,791 |
Understanding Compound Interest
Compound interest is interest calculated on both the principal and the accumulated interest from previous periods. Unlike simple interest (which only earns interest on the principal), compound interest grows exponentially over time.
Formula: A = P × (1 + r/n)^(n×t)
- A = Final amount (principal + interest)
- P = Principal (initial investment)
- r = Annual interest rate (decimal)
- n = Number of times interest is compounded per year
- t = Time in years
The Rule of 72: Divide 72 by the interest rate to estimate how many years it takes to double your money. At 8% annual rate, your money doubles in approximately 9 years (72 ÷ 8 = 9).
Frequently Asked Questions
Simple interest is calculated only on the original principal. Compound interest is calculated on the principal plus the interest already earned. For example, Rs.1 lakh at 10% for 3 years: Simple interest gives Rs.30,000 total interest, while compound interest (annual) gives Rs.33,100. The difference grows dramatically over longer periods — compound interest is significantly more powerful over 10+ years.
Compound interest is used by: Fixed Deposits (FDs), Recurring Deposits (RDs), Public Provident Fund (PPF — compounded annually), Employee Provident Fund (EPF), National Savings Certificate (NSC), mutual funds, and savings accounts. Loans (home loans, personal loans) also use compound interest — making it important to repay loans early to save on interest.
The more frequently interest compounds, the higher the final amount. Monthly compounding yields slightly more than annual compounding because interest starts earning interest sooner. However, the difference between monthly and daily compounding is minimal. What matters most for long-term wealth creation is the interest rate and the duration of investment — time is the most powerful variable in compounding.
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