I don't have a scale but the former owner was feeding him a mouse pup that was like 2 days old without its eyes open so I went up to a small he does great with it I tried medium one feed and he seemed to be having trouble getting it down so I went back to small. He is not that big around just long he is just a little over a foot long and he is big around as maybe a half dollar I don't know if that helps any with his size