# Diameter (Width) of a Circle

LAST UPDATE: February 2nd, 2022

## Method #1 – Diameter from Area

### Formula – How to calculate the diameter of a circle from the area

π is approximately 3.1415926535

Diameter = 2 x (√(Area ÷ π))

##### Example

A circle has an area of 10

Diameter = 2 x (√(10 ÷ π) = 2 x (√(10 ÷ 3.14159) = 2 x √(3.1831) = 2 x 1.7841 = 3.5682

## Method #2 – Diameter from Circumference

### Formula – How to calculate the diameter of a circle from the circumference

π is approximately 3.1415926535

Diameter = Circumference ÷ π

##### Example

A circle has a circumference of 10

Diameter = 10 ÷ π = 10 ÷ 3.14159 = 3.1831

## Method #3 – Diameter from Radius

### Formula – How to calculate the diameter of a circle using the radius

π is approximately 3.1415926535