The Sphynx cat is a Canadian hairless cat with a standard weight of about 3.5 to 7 kilograms. Generally, cats are basically out of shape when they grow to 8 to 10 months. There is a big difference between the cat's weight and feeding. relation. If you want your cat to grow heavier, you need to supplement nutrition before it is one year old. A normal cat's weight is one pound a month, and female cats will be smaller than male cats.