average weight of kittens by age
âNormal birth weight for kittens is approximately 3.5 to 4 ounces. The minimum weight gain expected for a kitten is approximately 0.5 oz. / day. By six weeks of age, kittens should weigh approximately one pound.â. âIf it is healthy, receiving adequate food and growing normally, it will gain an average of 4 oz per week until it is 6 months old.â.