In this python tutorial, you will learn about how to **calculate area of a circle in Python**, you can check the **Python program to calculate area of a circle** and, also we will check**:**

- Python program to calculate the area of a circle
- Python program to find the area of a circle using function
- Python program to find the area of a circle using the math module
- Python program to calculate the area and circumference of a circle
- Python program to calculate the area and circumference of a circle using an inbuilt math module
- Python program to find the area and perimeter of a circle
- Python program to calculate the area of a circle using class
- Python program to calculate the area and perimeter of a circle using class

## Python program to calculate area of a circle

Let see **python program to calculate the area of a circle**.

- Firstly, we will take input from the user using the
**input()**function for radius and store it in a variable. - We can use constant to store the value of
**‘pi’**. - Now, we will calculate the area of a circle by using the formula
**area = PI * r * r**. - And at last,
**print**the area of a circle to get the output.

**Example:**

```
PI = 3.14
r = float(input("Enter the radius of a circle:"))
area = PI * r * r
print("Area of a circle = %.2f" %area)
```

You can refer to the below screenshot to see the output for python program to calculate the area of a circle

The above code, we can use to **calculate area of a circle in Python**.

Also, read, Python program to find an area of a rectangle and How to find area of a triangle in Python?

## Python program to find area of a circle using function

Here, we will see **python program to find the area of a circle using function**.

- In this example, I have defined a function as
**def findArea(r)**. - We can store the value
**PI = 3.14**which is fixed. - The function is returned as
**return PI * (r * r)** - The function findArea(6) is called and it will print the output.

**Example:**

```
def findArea(r):
PI = 3.14
return PI * (r*r);
print("Area of circle = %.6f" % findArea(6));
```

You can refer to the below screenshot to see the output for the python program to find the area of a circle using the function.

The above python code to **find area of a circle using function in Python**.

## Find area of a circle using Python math module

Now, we will see **python program to find area of a circle using the math module**.

- In this example, we will
**import math**module which is an inbuilt module. - We will take the
**radius**as an input from the user. - Now, we will calculate the area of a circle by using the formula
**area = math.pi * r * r**. The value of**“pi”**is taken from the**“math”**module. - And at last,
**print**the area of a circle to get the output.

**Example:**

```
import math
r = float(input("Enter the radius of a circle:"))
area = math.pi * r * r
print("Area of a circle = %.2f" %area)
```

You can refer to the below screenshot to see the output for the python program to find the area of a circle using the math module.

The above code, we can use to **find area of a circle using Python math module**.

Also read, How to Create Countdown Timer using Python Tkinter.

## Python program to calculate area and circumference of a circle

Let’s see **python program to calculate the area and circumference of a circle**.

- Firstly, we will take input from the user using the
**input()**function for radius and store it in a variable. - We can use constant to store the value of
**‘pi’**. - Now, we will calculate the area of a circle by using the formula
**area = PI * r * r**. - And for calculating the circumference of a circle we will use the formula
**circumference = 2 * PI * r**. - And at last,
**print**the area and circumference of a circle to get the output. The value is formatted up to two decimal places using**%.2f**.

**Example:**

```
PI = 3.14
r = float(input(' Please Enter the radius of a circle: '))
area = PI * r * r
circumference = 2 * PI * r
print(" Area Of a Circle = %.2f" %area)
print(" Circumference Of a Circle = %.2f" %circumference)
```

You can refer to the below screenshot to see the output for the python program to calculate the area and circumference of a circle.

This is the Python program to calculate area and circumference of a circle.

You may like, Python program to find the area of square.

## Python program to calculate the area and circumference of a circle using an inbuilt math module

Here, we will see **python program to calculate the area and circumference of a circle using an inbuilt math module**.

- Firstly, we will
**import math**module which is an inbuilt module. - We will take input from the user using the
**input()**function for radius and store it in a variable. - Now, we will calculate the
**area of a circle**by using the formula**area = math.pi * r * r**. - And for calculating the
**circumference of a circle**we will use the formula**circumference = 2 * math.pi * r**. - And at last,
**print**the area and circumference of a circle to get the output. The value is formatted up to two decimal places using**%.2f**.

**Example:**

```
import math
r = float(input(' Please Enter the radius of a circle: '))
area = math.pi * r * r
circumference = 2 * math.pi * r
print(" Area Of a Circle = %.2f" %area)
print(" Circumference Of a Circle = %.2f" %circumference)
```

You can refer to the below screenshot to see the output for the python program to calculate the area and circumference of a circle using an inbuilt math module.

## Python program to find area and perimeter of a circle

Now, we will see **python program to find the area and perimeter of a circle**

- Firstly, we will take input from the user using the
**input()**function for**radius**and store it in a variable. - We have used
**3.14**the value of**pi**in the formula. - Now, we will calculate the
**area of a circle**by using the formula**area = 3.14* r * r**. - And for calculating the
**perimeter of a circle**we will use the formula**perimeter = 2*3.14*r** - And at last,
**print**the area and perimeter of a circle to get the output.

**Example:**

```
r=float(input("Enter the Radius of circle: "))
area = 3.14*r*r
perimeter = 2*3.14*r
print("Area of Circle: ",area)
print("Perimeter of Circle: ",perimeter)
```

You can refer to the below screenshot to see the output for the python program to find the area and perimeter of a circle.

The above code, we can use to **find area and perimeter of a circle in Python**.

## Python program to calculate area of a circle using class

Let see **python program to calculate the area of a circle using class**.

- In this example, we have created a
**class**named**“Circle”**and it has an attribute radius as r. - The constructor of the class initiates the attribute using the
**__init__**function. - We have used
**3.14**the value of**pi**in the formula. - The method
**“area”**is created to calculate the area of a given circle. - An instance of the class
**“Circle”**is created as**“obj”**and the method is invoked to display the output.

**Example:**

```
class Circle:
def __init__(self, r):
self.radius = r
def area(self):
return 3.14 * (self.radius ** 2)
obj = Circle(8)
print("Area of circle:",obj.area())
```

You can refer to the below screenshot to see the output for the python program to calculate the area of a circle using class.

The above Python code is to calculate area of a circle using class.

## Python program to calculate area and perimeter of a circle using class

Here, we will see **python program to calculate the area and perimeter of a circle using class**

- In this example, we have created a
**class**named**“Circle”**and it has an attribute radius as r. - The constructor of the class initiates the attribute using the
**__init__**function. - We have used
**3.14**the value of**pi**in the formula. - The two methods
**“area”**and**“perimeter”**are created to calculate the area of a given circle. - An instance of the class
**“Circle”**is created as**“obj”**and the method is invoked to display the output.

**Example:**

```
class Circle:
def __init__(self, r):
self.radius = r
def area(self):
return 3.14 * (self.radius ** 2)
def perimeter(self):
return 2*3.14*self.radius
obj = Circle(3)
print("Area of circle:",obj.area())
print("Perimeter of circle:",obj.perimeter())
```

You can refer to the below screenshot to see the output for the python program to calculate the area and perimeter of a circle using class.

You may like the following Python tutorials:

- How to calculate simple interest in Python
- Python program to print pattern
- How to print factorial of a number in Python
- How to swap two numbers in Python
- How to subtract two numbers in Python

In this Python tutorial, we have learned about the **Python programs to calculate the area of a circle**. Also, we covered these below topics:

- How to calculate the area of a circle in Python
- How to find the area of a circle using a function in Python
- How to find the area of a circle using the math module in Python.
- How to calculate the area and circumference of a circle in Python.
- Python program to calculate the area and circumference of a circle using an inbuilt math module
- How to find the area and perimeter of a circle in Python
- How to calculate the area of a circle using class in Python
- How to calculate the area and perimeter of a circle using class in Python.

I am Bijay Kumar, a Microsoft MVP in SharePoint. Apart from SharePoint, I started working on Python, Machine learning, and artificial intelligence for the last 5 years. During this time I got expertise in various Python libraries also like Tkinter, Pandas, NumPy, Turtle, Django, Matplotlib, Tensorflow, Scipy, Scikit-Learn, etcâ€¦ for various clients in the United States, Canada, the United Kingdom, Australia, New Zealand, etc. Check out my profile.