Simple Interest Calculator


Easily compute interest on loans or investments. Simplify financial planning and
understand the real cost of borrowing or lending.

Simple Interest Calculator

Principal Amount: ₹0
Est. return: ₹0
Total Payment: ₹0

What is Simple Interest?

Simple interest is a method used to determine the amount of interest accrued on a principal sum over a specified period at a fixed rate. In simple interest, the principal remains constant, making it a straightforward approach for interest calculation.
Simple interest offers a straightforward method for understanding the cost of borrowing. It calculates the interest rate based on the initial principal amount, which remains constant as long as payments are made punctually. There's no compounding interest or consideration of interest accruing on a growing balance.
This implies that, for loan terms exceeding one year, you'll consistently incur lower interest charges with a simple interest loan compared to a compound interest loan. Many debt agreements necessitate a more intricate interest calculation than simple interest.


Are there two Formulas for Simple Interest?

Yes, there are two formulas for calculating simple interest.
The first formula is Simple Interest (SI)= {P x R x T}x100, where P represents the principal amount, R is the rate of interest, and T is the Time period.
By rearranging this formula, we can solve for = (100 × SI)/(R × T), and similarly, we can solve for either R or T .
Another formulation sometimes used is: SI = PRT where R is the rate of interest as a decimal. i.e., if the rate of interest is 5% then R can be written as 5/100 = 0.05.


What are the different Forms of Simple Interest?

While the formula for computing simple interest remains consistent, it is categorized into two types: ordinary and exact. The discrepancy lies in the treatment of time within each category.
Ordinary simple interest utilizes 360 days as the standard number of days in a year.
Alternatively, exact simple interest employs the precise count of days in a year, which amounts to 365 days or 366 in a leap year.
Let`s illustrate this distinction with an example:
Suppose Sumit borrows ₹15,000 from a bank on June 1, 2020, to expand his small office, with an agreement to repay the loan by August 10, 2020, at a 6% rate of interest. The calculation proceeds as follows:
Principal amount: ₹15,000
Rate of Interest (ROI): 6%
Number of days from June 1 to August 10 = 29 + 31 + 10 = 70
Converting days into years: 70 days x 1/360 days = 7/36 years
Using the formula: Interest = (Principal x Rate x Time)/100
Interest: ₹15,000 x 6% x 7/36 = ₹175

Hence, Sumit`s total interest payment amounts to ₹175.
Now, let's examine how exact simple interest calculation differs:

Principal: ₹15,000
Rate: 6%
Time: 70/365 years
Interest calculation: ₹15,000 x 6% x 70/365 = ₹180

How do I Calculate a Simple Interest Rate?

To calculate the simple interest rate, you need to subtract the principal amount from the final amount, divide the result by the principal amount, and then multiply by 100. Let's illustrate this process with an example:
Suppose Sumit borrows ₹1,00,000 from a bank for a period of 1 year at an annual interest rate of 10%. Here's how sumit's loan account would appear at the end of the year:
Principal amount (P): ₹1,00,000
Annual interest rate (R): 10%
Time period (T): 1 year
Calculation of simple interest: (P x R x T)/100 = (1,00,000 * 10 * 1)/100 = ₹10,000

Therefore, Sumit has to repay the principal amount plus interest at the end of year 1, which equals ₹1,00,000 + ₹ 10,000 = ₹1,10,000.
Moreover, to determine the interest rate, the calculation proceeds as follows:
Interest rate % = [(₹1,10,000 – ₹1,00,000)/₹1,00,000] * 100 = 10%

How can I Compute Monthly Simple Interest?

The calculation of simple interest is straightforward using the formula provided below:
Simple interest = (Principal x Rate x Time)/100
How does Simple Interest Calculator Works? To illustrate this clearly, let's apply the formula to the following example:
Suppose you invest ₹5,00,000 in a fixed deposit account for 5 years, with an FD rate of 10%. Using the SI formula, the interest earned on your deposit would be calculated as follows:
SI = 5,00,000 x 10 x 5 ÷ 100 = ₹2,50,000
Total Amount at the end of 5 years = ₹5,00,000 + ₹2,50,000 = ₹7,50,000.
Consequently, you would receive an additional interest of ₹2.50 Lakh at the end of the 5-year maturity period.
Furthermore, the maturity amount of the Fixed Deposit would be ₹7.50 Lakh.

Which is Preferable, Simple or Compound Interest?

Simple interest, in contrast to compound interest, offers easier computation and comprehension. In scenarios involving temporary loans or those with non-compounding interest, the focus remains solely on the interest accumulated on the outstanding principal balance. For instance, mortgages and most car loans adhere to simple interest accrual without compounding.
On the other hand, when it pertains to investments, compound interest proves advantageous as it facilitates accelerated growth of funds compared to accounts with a simple interest structure. Compound interest becomes significant when computing the annual percentage yield, representing either the annual rate of return or the annual borrowing cost.

About Simple Interest Calculator

A simple interest calculator is a tool that helps you determine the interest earned or paid on a principal amount over a specified period of time, using the simple interest formula.

How does Simple Interest Calculator Works?

Simple Interest Calculator provides a straightforward method for calculating interest on loans or investments. Simple interest calculators are helpful for understanding the interest component of loans and investments without the compounding factor.

Simple Interest = P * r * t / 100
Where P is the principal amount,
r is the rate of interest,
and t is the time in years.

Advantages of Simple Interest Calculator

Easy and Quick Calculations: The simple interest calculator simplifies the process of calculating interest on loans or investments without the complexity of compounding.

Transparent Interest Computation: Users can easily understand how interest is computed over time, making it a useful tool for educational purposes and financial literacy.

Loan Comparison: It's valuable for comparing loans with different interest rates or durations, helping users make informed decisions about borrowing.

Budgeting Assistance: Individuals can use the simple interest calculator to plan for interest payments, aiding in budgeting and ensuring timely repayments.

Flexible for Varied Time Periods:The calculator accommodates different time periods for interest calculation, making it versatile for short-term and long-term financial planning.