← Back to Overview

Java Program - Simple Interest Calculator

Concept Explanation

What is it?

Simple interest is a quick and easy method of calculating the interest charge on a loan or investment. It is determined by multiplying the daily interest rate by the principal by the number of days that elapse between payments.

Formula

$$SI = \frac{P \times R \times T}{100}$$ Where:

• P = Principal amount
• R = Rate of interest per annum
• T = Time (in years)

---

Algorithm

1. Start
2. Declare variables for Principal (p), Rate (r), Time (t), and Interest (si).
3. Accept or initialize input values.
4. Apply the formula: si = (p * r * t) / 100.
5. Display the result.
6. End

---

Implementations

Java (JDK 17)

import java.util.Scanner;

public class SimpleInterest {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        System.out.print("Enter Principal Amount: ");
        double p = sc.nextDouble();

        System.out.print("Enter Annual Interest Rate (%): ");
        double r = sc.nextDouble();

        System.out.print("Enter Time (Years): ");
        double t = sc.nextDouble();

        double si = (p * r * t) / 100;

        System.out.println("-------------------");
        System.out.println("Simple Interest: " + si);
        System.out.println("Total Amount: " + (p + si));
        
        sc.close();
    }
}

---

Explanation

• Java
  • Uses java.util.Scanner for user input.
  • Uses double data type to handle decimal values for precision.
  • Ensures the formula order follows PEMDAS.

---

Complexity Analysis

• Time Complexity: O(1)
• Space Complexity: O(1)

---

Sample Dry Run

Principal	Rate	Time	Calculation	Output
1000	5	2	(1000 * 5 * 2) / 100	100

---

Related Concepts

• Arithmetic Operations
• Data Types

---

"Interest on debts is inventory's cousin." - Anonymous