Interest Rate Calculator

Compare simple and compound interest across compounding frequencies

Principal Amount

₹1 Thousand ₹1 Crore

Annual Interest Rate

1% 25%

Time Period

1 Year 25 Years

Interest Earned

Principal Amount

Interest Earned

Total Amount

Switch the compounding mode above to see how frequency changes the interest earned on the same headline rate.

About the Interest Rate Calculator

An interest rate calculator converts a headline rate into the actual money you earn or owe. It supports simple interest, where interest applies only to the principal, and compound interest, where interest earns further interest at yearly, half yearly, quarterly, or monthly rest. Comparing the two makes the real effect of compounding visible in rupees rather than percentages.

How Does the Interest Rate Calculator Work?

Simple interest: SI = P x R x T / 100

Compound interest: A = P x (1 + r/n)^(n x t)

P is the principal amount.
R or r is the annual interest rate.
T or t is the time in years.
n is the compounding frequency per year, for example 1 for annual and 4 for quarterly.

Example

Take Rs. 50,000 at 8% per year for 3 years. Simple interest adds Rs. 12,000 for a total of Rs. 62,000. Compounded annually, the total becomes Rs. 62,986, and compounded quarterly, Rs. 63,412. The same headline rate produces three different outcomes purely because of how interest is applied.

Comparison of Rs. 50,000 at 8% for 3 years

Interest Earned
Simple interest	Rs. 12,000	Rs. 62,000
Compound interest, annually	Rs. 12,986	Rs. 62,986
Compound interest, quarterly	Rs. 13,412	Rs. 63,412

How to Use the Interest Rate Calculator

Enter the principal amount.
Enter the annual interest rate.
Set the time period and the compounding frequency.
Compare simple and compound results side by side.

Benefits of Using the Interest Rate Calculator

Shows the true cost of loans and the true yield of deposits.
Reveals how frequency of compounding changes outcomes.
Useful for converting flat rates into effective annual rates.
Instant results with no signup.

Frequently Asked Questions

What is the difference between simple and compound interest?

Simple interest is charged only on the original principal, while compound interest is charged on principal plus accumulated interest. Over long tenures the gap between the two grows very large.

How often do banks compound deposit interest?

Most Indian banks compound fixed deposit interest quarterly. Savings account interest is usually calculated on daily balances but credited quarterly or monthly depending on the bank.

What does compounding frequency mean?

It is how many times a year interest is added to the balance. More frequent compounding increases the effective annual yield at the same headline rate, which is why a 8% quarterly compounded deposit yields slightly more than 8%.

Is compound interest good or bad?

It is good when you are earning, as in deposits and investments, and costly when you are borrowing, as in credit cards and some loans. The same math works both ways.

Can I convert a flat loan rate into an effective rate?

Yes. Flat rates on vehicle loans often look lower than reducing balance rates, but the effective rate is nearly double. Our EMI calculator shows the real cost through the monthly installment itself.

Disclaimer: The Interest Rate Calculator provides estimates for educational purposes only and is not investment advice. Actual returns, rates, and charges depend on the product provider and market conditions. Verify details on the official website and consult a financial advisor before investing.

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