How heavy are Kingfish pit bulls? Written by Russel in A How heavy are Kingfish pit bulls? Kingfish Pitbulls were bred as game dogs hence adopted lean bodies. A full-grown Kingfish pitbull weighs about 35 to 60 pounds. Inbreeding helps maintain this desirable weight in Kingfish Pitbulls. Russel A pet owner who loves to share useful facts and information about animals. For now, I write mostly about dogs and cats.