C++ Exercises: Calculate Simple Interest

Last update on August 11 2025 12:58:12 (UTC/GMT +8 hours)

Simple Interest Calculation

Write a C++ program to enter P, T, R and calculate Simple Interest.

Sample Solution:

C++ Code :

#include<iostream> // Including input-output stream header file
using namespace std; // Using the standard namespace

int main() { // Start of the main function

    int p, r, t, i; // Declaring variables to store principle, rate, time, and interest

    cout << "\n\n Calculate the Simple Interest :\n"; // Displaying the purpose of the program
    cout << " -----------------------------------\n"; 

    cout << " Input the Principle: "; // Prompting the user to input the principle amount
    cin >> p; // Taking input of the principle amount from the user

    cout << " Input the Rate of Interest: "; // Prompting the user to input the rate of interest
    cin >> r; // Taking input of the rate of interest from the user

    cout << " Input the Time: "; // Prompting the user to input the time period
    cin >> t; // Taking input of the time period from the user

    i = (p * r * t) / 100; // Calculating the simple interest using the formula: PRT / 100

    cout << " The Simple interest for the amount " << p << " for " << t << " years @ " << r << " % is: " << i; // Displaying the calculated simple interest

    cout << endl; // Displaying an empty line for better readability
    return 0; // Returning 0 to indicate successful program execution
}

Sample Output:

 Calculate the Simple Interest :                                       
 -----------------------------------                                   
 Input the Principle: 20000                                            
 Input the Rate of Interest: 10                                        
 Input the Time: 1.5                                                   
 The Simple interest for the amount 20000 for 1 years @ 10 % is: 2000

Flowchart:

For more Practice: Solve these Related Problems:

Write a C++ program to compute simple interest, including error handling for negative principal, rate, or time values.
Write a C++ program that calculates simple interest and then outputs a summary report comparing the interest earned over different time periods.
Write a C++ program to compute simple interest and then determine the effective annual interest rate from the computed interest.
Write a C++ program that accepts principal, rate, and time as inputs, calculates simple interest, and formats the output as a financial report.

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C++ Code Editor:

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