Simple Interest Calculator

Enter the principal amount, interest rate, period, and frequency to quickly determine the interest earned. Start estimating your interest.

Principal Amount




Rate of Interest (P.A)




Time period




Principal Amount


Total Interest


Amount in 10 Yr.


Principal Amount


Interest is the money you receive for locking-in or lending money. When interest is not compounded, it is called simple interest. And this calculator will help you estimate it. Whether you are taking a loan or putting your money in saving, simple interest calculators are a must-use. Let’s learn more about them below.

Explained: Simple interest calculator

A simple interest calculator is a tool to compute the simple interest on loans or savings. It take the principal amount, annual interest rate, and investment period on board. Once these details are in place, the calculator estimates the interest in a few seconds.

How to calculate simple interest using calculator

When a borrower repays the money they owe, the lender receives a sum of money in addition to the principal amount. (The borrowed amount is known as the principal.) The additional amount the borrower pays for holding on to the money for a specified period is called the interest. To calculate this simple interest, use our calculator. Simply enter the principal amount, the number of periods of investment, and the interest rate, and voila, there you have it—the simple interest.


Alternatively, you could use the formula below.

What is the formula for calculating simple interest?

To calculate simple interest, one must multiply the interest rate by the principal amount and the time in years. As a formula, this may be presented as follows:


Simple Interest (SI) = P × T × R ⁄ 100


In the equation above:

P = Initial principal balance

r = Annual interest rate

t = Time (usually in years)

How do simple interest calculators work?

Calculating simple interest with the calculator above is easy and quick. Simply follow the basic few steps below:


Step 1: Go to the online SI calculator page.


Step 2: Select the interest type as simple interest.


Step 3: Enter the principal amount.


Step 4: Enter the annual rate of interest.


Step 5: Choose the timeframe—days, months, or years.


Our simple interest calculator display the interest based on the inputs you provide.

How can the simple interest calculator help you?

A simple interest calculator, like the one above, can be incredibly helpful. Among other things, it can:

  • Calculate the interest earned on investments accurately.
  • Aid investors while comparing the projected returns of various investments.
  • Determine how long it will take for an investment to reach a specific maturity value.
  • Adjust the principal, interest rate, or time period, so users can explore different scenarios and optimize their investment strategies.
  • Save time and help avoid the human errors that creep in with manual calculation.

Benefits of simple interest calculator

There are various other benefits of using a calculator of this kind. Let’s look at some of them here.

  • Effective calculation

The manual method of calculating interest on savings or loans may be riddled with errors. Switching to an online calculator can save you from them.


They also offer flexibility while calculating interest, so you can factor in various time periods and interest rates.

  • Saves time

Calculating simple interest manually can be time-consuming. Users factor in multiple scenarios with various types of data—principal amount, interest rate and duration. And with an online calculator, all scenarios are accounted for in a shorter period of time.

  • Determines current value of money

SI calculators help calculate the interest earned or accrued over a specific period. This helps individuals understand the growth or depreciation of their money over time, which enables them to make informed decisions regarding savings or loan repayments. 

  • Helps find the total return and maturity time 

Apart from all the benefits stated above, the SI calculator can also help determine the total return and maturity time of an investment or loan.


A simple interest calculator is a great financial tool as it allows for easy calculation of interest. Anyone can use it to understand the costs and gains involved. It helps in financial planning and enables comparison of options. Its simplicity and easy to use interface makes it a tool which can be accessed by all.


1. What can I determine with the help of SI calculators?

Simple Interest calculators are a useful tool for anyone interested in wealth creation. The calculator determines interest on loans or savings without compounding. It allows investors to calculate the interest on the principal amount—whether on a daily, monthly, or yearly basis.

2.Can I change the unit of the amount to different currencies?

Yes, the unit of the amount can be changed.

3.How do you calculate interest for six months?

To calculate the interest for six months, you can simply use our calculator. However, you will need a few details: 1. The principal amount (P); 2. The interest rate per annum (R) divided by 2; and 3. The time period (T) by 2.

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