# C++ Program to Calculate the Simple Interest

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In this tutorial, we will learn about Simple Interest in C++ i.e. how to write a program to calculate the simple interest using C++.

## Quick Info:ðŸ’¡

â†ª As we know, Simple Interest(S.I) is a quick and easy method of calculating the interest charge on a loan.

â†ª For calculating the Simple interest, we require parameters like principal(P), rate(R) and time(T). The formula for calculating Simple Interest is (P*R*T)/100.

â†ª Hereâ€™s the following steps to calculate the Simple Interest:

• First, initialize the variables- principal, rate, time and SI.
• Second, find the Simple interest using formula.
• Third, print the result of SI on the output console.

Code to calculate simple interest can be performed in two ways:

## Program to Calculate Simple Interest Using Direct Method

Hereâ€™s a direct method to calculate Simple Interest.

Simply, the user will be asked to enter the values then, the result is computed according to code provided and then displayed to a user.

### Example:

``````#include<iostream.h>
#include<conio.h>
void main()
{
int simple_interest,principal,rate,time;
cout<<"Enter principal";
cin>>principal;
cout<<"Enter rate";
cin>>rate;
cout<<"Enter time";
cin>>time;
simple_interest=(principal*rate*time)/100;
cout<<"Simple Interest is:="<<simple_interest;
getch();
}``````
``````//Output:
Enter principal 12000
Enter rate 2
Enter time 2
Simple Interest is:=480``````

### Working:

Flow of the program internally:

## Program to Calculate Simple Interest Using Function

Functions are used to perform certain actions, and they are important for reusing code: Define the code once and use it many times.

And, this is a another method to calculate Simple Interest at large amount i.e. by function.

Note: Always remember that execution starts from the main body only.

### Example:

``````#include<iostream.h>
#include<conio.h>
double SI(double principal, double rate, double time)
{
double simple_interest;
simple_interest=(principal*rate*time)/100;
return simple_interest;
}
double main(){
double SI1=SI(12000,2,2);
double SI2=SI(5500,2,3.5);
cout<<"Simple Interest for SI1 is:="<<SI1<<endl;
cout<<"Simple Interest for SI2 is:="<<SI2<<endl;
getch();
return 0;
}``````
``````//Output:
Simple Interest for SI1 is:=480
Simple Interest for SI2 is:=385``````

## Working:

Flow of a program:

Well, I hope it really helped you to know C++ better.

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