Calculate the Area of a Circle

This will calculate the area of a circle based on its diameter. Confused as to what diameter means? Scroll down for a diagram.
Area of a 10′6″ diameter circle
86.590square feet
12,469square inches
9.6211square yards
8.0445square meters
80,445square centimeters
(results may be rounded)

Area of a Circle Formula

The area of a circle is pi times the square of its radius. The radius is half the diameter.

Area = π * (Diameter / 2)2

Diameter of a Circle

The diameter of a circle is the distance from one edge to the other, passing through the center. It is twice the radius.