In this blog post, we’ll explore a straightforward Python program that calculates the simple interest for a borrowed amount. Understanding how to calculate simple interest is a useful financial skill, and this program will help you grasp the basics of Python programming and arithmetic operations.
What is Simple Interest?
Simple interest is a way to calculate the interest charged or earned on a principal amount over a specified period at a fixed rate. The formula for simple interest is:
[ \text{Simple Interest} (SI) = \frac{P \times R \times T}{100} ]
Where:
- ( P ) = Principal amount (the initial amount of money borrowed or invested)
- ( R ) = Rate of interest (annual interest rate in percentage)
- ( T ) = Time period (in years)
The Program
Let’s walk through a Python program that calculates simple interest based on user input.
Python Code
# Step 1: Take input from the user
borrowed_amount = float(input("Enter the borrowed amount: "))
period_years = int(input("Enter the period in years: "))
rate_of_interest = float(input("Enter the rate of interest: "))
# Step 2: Calculate the simple interest
simple_interest = (borrowed_amount * rate_of_interest * period_years) / 100
# Step 3: Print the calculated simple interest
print(f"The simple interest for the borrowed amount is: {simple_interest:.2f}")Explanation of the Code
- Input:
borrowed_amount = float(input("Enter the borrowed amount: ")): This line prompts the user to enter the amount of money borrowed. Thefloat()function converts the input into a floating-point number to handle decimal values.period_years = int(input("Enter the period in years: ")): This line prompts the user to enter the period in years. Theint()function ensures the input is an integer.rate_of_interest = float(input("Enter the rate of interest: ")): This line prompts the user to enter the rate of interest. Thefloat()function converts the input into a floating-point number.
- Calculate Simple Interest:
simple_interest = (borrowed_amount * rate_of_interest * period_years) / 100: This line uses the simple interest formula to calculate the interest. It multiplies the borrowed amount by the rate of interest and the period in years, then divides by 100 to get the interest amount.
- Output:
print(f"The simple interest for the borrowed amount is: {simple_interest:.2f}"): This line prints the calculated simple interest, formatted to two decimal places for clarity.
Example Test Cases
Let’s see how the program works with a few example inputs:
- Example 1:
- Input:
- Borrowed amount:
1000 - Period in years:
3 - Rate of interest:
5.0
- Borrowed amount:
- Output:
The simple interest for the borrowed amount is: 150.00 - Explanation: Simple interest = ( \frac{1000 \times 5.0 \times 3}{100} = 150.00 )
- Example 2:
- Input:
- Borrowed amount:
2000 - Period in years:
2 - Rate of interest:
4.5
- Borrowed amount:
- Output:
The simple interest for the borrowed amount is: 180.00 - Explanation: Simple interest = ( \frac{2000 \times 4.5 \times 2}{100} = 180.00 )
- Example 3:
- Input:
- Borrowed amount:
500 - Period in years:
5 - Rate of interest:
6.0
- Borrowed amount:
- Output:
The simple interest for the borrowed amount is: 150.00 - Explanation: Simple interest = ( \frac{500 \times 6.0 \times 5}{100} = 150.00 )
- Example 4:
- Input:
- Borrowed amount:
1500 - Period in years:
4 - Rate of interest:
3.5
- Borrowed amount:
- Output:
The simple interest for the borrowed amount is: 210.00 - Explanation: Simple interest = ( \frac{1500 \times 3.5 \times 4}{100} = 210.00 )
Conclusion
This simple Python program demonstrates how to calculate simple interest using basic arithmetic and string operations. By understanding and implementing this program, you gain insight into handling user inputs, performing calculations, and formatting output in Python. This foundational knowledge is essential for more advanced programming and financial computations.