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.
Circle Area Formulas
To calculate the area of a circle, you’ll need the radius, diameter, or circumference.
Then, use one of the following formulas.
Find Area Using Radius
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.
Find Area Using Diameter
The formula to find the area using the diameter is:
A = π × (d2)²
The area A is equal to pi times the diameter divided by 2, squared.
Find Area Using Circumference
The formula to find the area using the circumference is:
A = π × (C2π)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.