What is the size of a silkie chicken?

About the size o a volleyball

Sources: own them

Added:

Silkies come in both Bantam and Standard sizes.

However, the Standard size itself isn't very big with Roosters averaging 4 pounds and hens averaging 3 pounds.

The Bantam variety that is more common in the US and represented in the APA, lists Roosters at 36 oz and hens at 32 oz.