The Circle calculator help in finding the area, diameter and circumference of a circle.

**Definition of a circle:**: A circle is a closed
plane curve that divides the plane into two regions, an interior
and an exterior, such that every point on the curve is at a
fixed distance from a fixed point. The fixed point is called the
centre and the distance is called the radius.

Circle calculator is a simple online tool to calculate the area of a circle given the radius. The calculator can be used to find the area of a circle from any sized radius. After typing the required input you will see the results in the form of a circle area equivalent to the radius you have entered. The formula for calculating the area of a circle is: A = πr² where r is the radius.

- Area of circle = πr²
- Circumference of circle = 2πr
- diameter of circle = 2r

The fixed point is called the centre in the given picture 'o' is the centre of the circle. The curve is the locus of a point that is at a constant distance from a given point called the centre. The distance between the centre and the point is called the radius and the point is called the centre.

A radius is the fixed distance from a circle's centre. The radius is a non-changing distance from a circle's centre. If a circle is perfect, then the radius will always be the same. However, in the real world, a radius can change. A radius can be measured from an infinite amount of points, but there is always a fixed distance from the centre of the circle. There are many uses for a radius, but it can be used to find the circumference and area of a circle.

A diameter of a circle is a line segment passing through the center and joins the two points on the circle. A diameter is the longest distance between two points on the circle. The distance between any two points on a circle is always half the diameter. A diameter is usually denoted by the symbol d.

Diameter = 2 x radius

A diameter of a circle is a line segment passing through the centre and joining the two points on the circle. Diameter is the longest distance between two points on the circle. The distance between any two points on a circle is always half the diameter. Diameter is usually denoted by the symbol d.

Circumference = 2π x radius

Enter only radius value in the proper input field and then click calculate, you see calculate the value in answer box with formula but if you want to enter another value so first clear the entered value then after entering new radius value.

Radius(Unit) | Diameter | Area | Circumference |
---|---|---|---|

1 | 2 | 3.14159 | 6.28319 |

5 | 10 | 78.53982 | 31.41593 |

10 | 20 | 314.15927 | 62.83185 |

20 | 40 | 1256.63706 | 125.66371 |

50 | 100 | 7853.98163 | 314.15927 |

**Example.:-**Circle of Radius = 10 cm, find the
area of a circle, the circumference of circle and diameter of
the circle Area of circle = πr² = 314.15927 cm²

**Area of circle = **πr² = 314.15927 cm²

**Circumference of circle = **2πr = 62.83185 cm

**Diameter of circle = **2r = 20 cm

**Thanks**💙