# Area of a Circle Calculator

Calculate the area of a circle using the radius, diameter, or circumference with the circle area calculator.

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## How to Calculate the Area of a Circle

A circle is a round shape with no corners or edges where each point along its edge is equidistant from the center. The area of a circle is the amount of space the shape occupies.

Think of the area of a circle as the region of a two-dimensional plane it occupies or encloses.

There are a few ways to find the area of a circle.

The first way to calculate area is to use the circle area calculator above. The second way is to use a circle area formula.

### Circle Area Formulas

To calculate the area of a circle, you’ll need its radius, diameter, or circumference.

Then, use one of the following formulas.

#### Find Area Using Radius

The radius is the length of a straight line from the center of a circle to the outer edge. The most commonly used formula to find the area given the radius of a circle is:

A = π × r²

Thus, the area of a circle *A* is equal to pi times the radius *r* squared.

#### Find Area Using Diameter

The diameter is the length of a straight line from one edge of the circle to the opposite edge. It is twice the length of the radius.

The formula to find the area given the diameter of a circle is:

A = π × (d / 2)²

The area *A* is equal to pi times the diameter *d* divided by 2, squared.

#### Find Area Using Circumference

The circumference is the length of the outer edge around the perimeter of the circle. The formula to find the area given the circumference of a circle is:

A = π × (C / 2π)²

The area *A* is equal to pi times the circumference *C* divided by 2 times pi, squared.

Give our circle calculator a try and solve a circle’s dimensions, including the radius, diameter, and circumference.