# C Program To Calculate Simple Interest

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, let’s begin this tutorial.

Contents

## C Program To Calculate Simple Interest

```// C Program To Calculate Simple Interest
#include <stdio.h>
int main(){
float principal, time, rate, SI;

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.