Area of a Circle Calculator

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

How to Calculate the Area of a Circle

The area of a circle is the space occupied by the shape. 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.

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

Then, use one of the following formulas.

The formula to find the area using the radius is:

A = π × r²

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

The formula to find the area using the diameter is:

A = π × (d / 2)²

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

The formula to find the area using the circumference is:

A = π × (C / 2π)²

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

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