Area of a 9 Inch Circle

What is the area of a circle with a DIAMETER of 9 inches (radius of 4.5 inches)? How big is a 9 inch circle?
ft
in
Area of a 9″ diameter circle
63.617square inches
0.44179square feet
0.049087square yards
410.43square centimeters
0.041043square meters
(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.

Diameter
Circle Area by Diameter
(results are rounded)
Diameter in2 ft2 cm2
9.0 in 63.62 0.4418 410.4
9.1 in 65.04 0.4517 419.6
9.2 in 66.48 0.4616 428.9
9.3 in 67.93 0.4717 438.3
9.4 in 69.40 0.4819 447.7
Diameter in2 ft2 cm2
9.5 in 70.88 0.4922 457.3
9.6 in 72.38 0.5027 467.0
9.7 in 73.90 0.5132 476.8
9.8 in 75.43 0.5238 486.6
9.9 in 76.98 0.5346 496.6