 # Write a Program to Calculate Simple Interest in Python

## The objective of this Python post, you will see various Python examples that cover the following:

• Write a Program to Calculate Simple Interest in Python
• Simple Interest Program in Python using Function

Let us have a look at the formula for calculating the simple interest.

#### (P * N * R)/100

Where,
P is the principal amount
R is the rate and
N is the time span

Now let’s see each one by one:

### 1: Write a Program to Calculate Simple Interest in Python

• Use a python input() function in your python program that takes an input from the user.
• Next, calculate the simple interest using this SI = (P * N * R)/100  formula.
• After the end program, print the simple interest.
```#Python program to calculate simple interest

P = float(input("Enter the principal amount : "))

N = float(input("Enter the number of years : "))

R = float(input("Enter the rate of interest : "))

#calculate simple interest by using this formula
SI = (P * N * R)/100

#print
print("Simple interest : {}".format(SI))
```

Output

```Enter the principal amount :  1000
Enter the number of years :  2
Enter the rate of interest :  5
Simple interest : 100.0 ```

### 2: Simple Interest Program in Python using Function

• Define a function in your python program that accepts the argument and calculate simple interest by using this SI = (P * N * R)/100 formula.
• Use a python input() function in your python program that takes an input from the user.
• Next, call a simple interest function with specific arguments.
• After the end program, print the simple interest.
```#Python program to calculate simple interest using function

def simpleInterest(P, N, R):
SI = (P * N * R)/100
return SI

P = float(input("Enter the principal amount : "))

N = float(input("Enter the number of years : "))

R = float(input("Enter the rate of interest : "))

#calculate simple interest by using this formula
SI = simpleInterest(P, N, R)

#print
print("Simple interest : {}".format(SI))
```

Output

```Enter the principal amount :  1000
Enter the number of years :  2
Enter the rate of interest :  5
Simple interest : 100.0 ```