# Circumference of a circle Calculator

**Circumference of a circle -** is the length of the boundary of the circle. If we cut open the circle and straighten it the length of the boundary will be the measure of the circumference of the circle.

### What is meant by Circumference of a Circle?

Circumference or Perimeter is usually the measurement across the boundary of two-dimensional shapes including the circle. In other words, Circumference is the enclosing region for any geometric figure. It is the length of the circle. If you open up the boundary of the circle is opened it will be straightened up to a line segment its length is the circumference.

When we want to evaluate the Circumference using the formula we need to have either radius or diameter.

### How to Calculate Circumference of a Circle?

Circumference or perimeter of a circle can be calculated using a simple formula.

Circumference or Perimeter of Circle C =** 2πR**

in which R is the radius of the circle and π is a mathematical constant.

If the diameter of a circle Circumference can be calculated using another formula i.e. C =**π D**

In this D is the diameter of the circle and π is a mathematical constant.

**Example**

Calculate the Circumference of a Circle if the radius is given as 5 Cm?

**Solution: **

Given the Radius of Circle = 5cm

Substitute the given radius in the Circumference Formula and on doing so you will get it as under

Usually, C = 2πr

= 2*3.14*5

**= 31.4 Cm**

### How to use Circumference of Circle Calculator?

Go through these simple steps on how to use the calculator to find the circumference. You will land at the output very easily with this handy tool.

- Firstly, give the input in the field provided.
- After that, you can click on the metric you want be it cm,m, ft, yd, mi, etc. and then enter the circumference.
- You will get the Circumference in the output field.

### FAQs on Circumference of a Circle

**1. What is meant by Circumference of a Circle?**

Circumference or Perimeter of a circle is usually the measurement across the boundary of the circle. In other words, the circumference is the length of the circle.

**2. How do I calculate the circumference of a circle?**

You can calculate the Circumference of a Circle by using the formula C= 2πr.

**3. What is the Circumference of Circle with radius 7 cm?**

Circumference of Circle = 2πr

= 2*3.14*7

= 43.96 cm

**4. How to Calculate Diameter using Circumference?**

Circumference =**π D**

and Diameter D = **Circumference/π**

Thus, the diameter of a circle is the ratio between Circumference and **π.**