In this post, we will learn **how to calculate simple interest using C** Programming language.

**Simple Interest** is a method to calculate the amount of interest charged on a sum at a given rate and for a given period of time. In simple interest, the principal amount is always the same.

**Simple Interest **is calculated using the formula **S.I. = P x R x T**, where **P = Principal Amount**, **R = Rate of Interest** in **% **per annum and **T = Time **usually calculated as the number of years.

We will be using the same formula in our program to calculate the simple interest.

So, without further ado, letâ€™s begin this tutorial.

**C Program To Calculate Simple Interest**

// C Program To Calculate Simple Interest #include <stdio.h> int main(){ float principal, time, rate, SI; // Asking for Input printf("Enter the principal amount: "); scanf("%f", &principal); printf("Enter the time period: "); scanf("%f", &time); printf("Enter the rate of interest: "); scanf("%f", &rate); SI = (principal * time * rate) / 100; printf("Simple Interest for Principal Amount %.2f is %.2f", principal, SI); return 0; }

**Output**

```
Enter the principal amount: 18000
Enter the time period: 2
Enter the rate of interest: 6
Simple Interest for Principal Amount 18000.00 is 2160.00
```

**How Does This Program Work ?**

** float principal, time, rate, SI;**

In this program, we have declared four **float data type** variables named as **principal**, **time**, **rate** and **SI**.

** // Asking for Input
printf("Enter the principal amount: ");
scanf("%f", &principal);
printf("Enter the time period: ");
scanf("%f", &time);
printf("Enter the rate of interest: ");
scanf("%f", &rate);**

Then, the user is asked to enter the values of principal amount, rate of interest and time period.

` `** SI = (principal * time * rate) / 100;**

We calculate the Simple Interest using the formula **(P x R X T) / 100**. The value of simple interest gets stored in **SI** named variable.

` `**printf("Simple Interest for Principal Amount %.2f is %.2f", principal, SI);**

Then, simple interest for the principal amount is printed using **printf() **function. We have used **%.2f** format specifier because we want to display the result only till **2** decimal places.

**Conclusion**

I hope after going through this post, you understand **how to calculate simple interest using C** Programming language.

If you have any doubts regarding the program, feel free to contact us in the comment section. We will be delighted to help you.

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