Area of a 18 Inch Circle

What is the area of a circle with a DIAMETER of 18 inches (radius of 9 inches)? How big is a 18 inch circle?

Area of a 18″ diameter circle

(results may be rounded)

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

Area = π * (Diameter / 2)²

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

Circle Area by Diameter

(results are rounded)

Diameter	in²	ft²	cm²
18.0 in	254.5	1.767	1,642
18.1 in	257.3	1.787	1,660
18.2 in	260.2	1.807	1,678
18.3 in	263.0	1.827	1,697
18.4 in	265.9	1.847	1,716

Diameter	in²	ft²	cm²
18.5 in	268.8	1.867	1,734
18.6 in	271.7	1.887	1,753
18.7 in	274.6	1.907	1,772
18.8 in	277.6	1.928	1,791
18.9 in	280.6	1.948	1,810