By definition, a baseball is "9 to 9.25 inches or 22.86 to 23.495 centimeters in circumference." That means that the diameter is between 2.864788975 and 2.944366447 inches or 7.276564 and 7.478691 centimeters (an average of 2.904577711 inches or 7.377627 centimeters). What is the size of cricket ball? The ball, when new, shall weigh not less than 5 1/2 ounces/155.9g, nor more than 5 3/4 ounces/163g, and shall measure not less than 8 13/16 in/22.4cm, nor more than 9 in/22.9cm in circumference. Arnold Never liked baseball, the real ball is round and kicked around by folks wearing shorts. On 07/05/12, John T Lonsdale wrote: A cricket ball is a bit bigger than a hardball (baseball) and real men catch it without wearing huge padded gloves :) All the best, J.