Area of a 21 Inch Circle

What is the area of a circle with a DIAMETER of 21 inches (radius of 10.5 inches)? How big is a 21 inch circle?
ft
in
Area of a 21″ diameter circle
346.36square inches
2.4053square feet
0.26725square yards
2,234.6square centimeters
0.22346square 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
21.0 in 346.4 2.405 2,235
21.1 in 349.7 2.428 2,256
21.2 in 353.0 2.451 2,277
21.3 in 356.3 2.474 2,299
21.4 in 359.7 2.498 2,321
Diameter in2 ft2 cm2
21.5 in 363.1 2.521 2,342
21.6 in 366.4 2.545 2,364
21.7 in 369.8 2.568 2,386
21.8 in 373.3 2.592 2,408
21.9 in 376.7 2.616 2,430