Area of a 40 Centimeter Circle

What is the area of a circle with a DIAMETER of 40 cm (radius of 20 cm)? How big is a 40 centimeter circle?

Diameter

meters

Diameter

yards

Units

Area of a 40cm 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 may be rounded

Diameter	cm²	in²	ft²
40.0 cm	1,257	194.8	1.353
40.1 cm	1,263	195.8	1.359
40.2 cm	1,269	196.7	1.366
40.3 cm	1,276	197.7	1.373
40.4 cm	1,282	198.7	1.380
40.5 cm	1,288	199.7	1.387
40.6 cm	1,295	200.7	1.394
40.7 cm	1,301	201.7	1.400
40.8 cm	1,307	202.6	1.407
40.9 cm	1,314	203.6	1.414