How Does a Bank Calculate Interest on Your Fixed Deposit?

Personal Finance

A fixed deposit is a simple and safe investment. It only requires a one-time deposit. You can deposit a sum of money known as the “principal” with a bank for a set period. You will receive your deposit plus interest at the end. No matter how interest rates move or the economy performs, you will get fixed returns when investing. This helps you collect a large amount with ease.

What is a fixed deposit?

Fixed deposits (FDs) are a type of investment product banks offer. In this type of investment, investors put in a fixed amount of capital at a fixed interest rate for a fixed period. When the fixed deposit matures, the bank returns the principal amount as well as the interest earned.

Fixed deposits pay a higher interest rate than other products, such as savings accounts. You can put money into a fixed deposit for a set period, ranging from 7 days to 10 years. Anyone with a bank account can open an FD with a minimum deposit of Rs. 1,000. The minimum time frame is seven days.

How does a Bank Calculate Fixed Deposit Interest? 

Bank Calculates Interest on Fixed Deposit:

Simple interest and compound interest are the two methods for calculating interest on a fixed deposit. Banks may use either, depending on the deposit’s tenure and size.

Simple Interest

This method is simple. It is computed by multiplying the principal, interest rate, and period.

Simple Interest  –

“principal x rate of interest x time period divided by 100” or “P x Rx T/100.”


P = principal amount; R = annual interest rate T is the number of periods.

For example, if you invest Rs. 10,000 at 8% p.a. for 5 years, the interest can be calculated as follows:

Step 1: 10,000 times 8 times 5 equals Rs. 4,000,000.

Step 2: Divide that number by 100. You will be paid Rs. 4,000.

So, after 5 years, you will have earned Rs. 4,000 in interest.

As a result, if you invest Rs. 10,000 in a fixed deposit paying 8% p.a. simple interest over 5 years, you will receive Rs. 14,000 back.

Compound Interest 

In this method, you earn interest on both the principal and the interest. Many banks offer compound to calculate interest on fixed deposits, but you should shop around to ensure you get a good rate.

For example, suppose a bank offers 8% p.a. on a 5-year deposit with annual compounding. So, if you invest Rs. 10,000, the interest can be calculated as follows:

In the first year, we employ the simple interest method.

10,000x8x1/100 = Rs.800

So the first year’s interest is Rs. 800.

This sum is returned to the principal. As a result, the second-year principal’s salary is Rs. 10,800.

We can now compute the compound interest for the next three years in this manner.

Calculate Interest Fixed Deposits Using the fixed deposit calculator 

While the formulas are direct and can be used by banks to calculate the fixed deposit yield interest rate, it is a technical calculation. As a result, fixed deposit calculators are available to assist you in rightly and easily calculating the possible interest.

The fixed deposit calculator is an online tool. It requires you to enter the deposit amount, the deposit tenure, and the interest rate. The calculator then calculates the interest rate on the deposit as well as the amount due at maturity. You can also adjust the deposit amount to see how the interest earnings change.

The formula for calculating the final amount using a compound interest rate is as follows:

A=P [1+(r/12)/100)]



The amount at the end of the investing period is denoted by A.

P is the initial investment amount.

R: annualised interest rate, for example, 6, 6.5, or 7.

N: Is the investment tenure


A fixed deposit is an investment scheme. In this, you deposit a lump-sum amount with a bank or financial institution for a specific period. As a reward for this lump sum, you will receive a certain percentage of interest. At the end of the fixed period, the financial institution returns your principal investment amount as well as the interest earned up to that point.

Fixed deposits are generally thought to be far safer than other types of investments. Fixed deposits have low default risk. However, the default risk is not non-existent. You risk losing your investment capital if you invest in low-rated fixed deposits.

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  1. What is the definition of compound interest? What is the compound interest formula for a fixed deposit?

Fixed-Deposit Compound Interest

Compound interest is interest earned on both the principal and interest earned. The interest rate is increased in proportion to the number of periods (years) for which the interest will be compounded and multiplied by the principal amount invested.

Calculate interest on FD using compound interest

P (1 + r/n) (n * t) A

“A stands for maturity amount.

P denotes the principal invested.

R = The interest rate (in decimals)

N is the number of compounds that occur in a year.

T denotes the number of years.

  1. What is the minimum term for which a fixed deposit can be held?

Customers can choose to invest their money for as little as 7 days and as much as 10 years.

  1. What are the drawbacks of a fixed deposit?Fixed deposits have drawbacks.
    • Lower interest rates No interest increases
    • Inflation can cause interest rates to fall.