I have a male kitten that I adopted 2 weeks ago. The Shelter told me is was 4 months old (although I am not sure if their paperwork had been updated since they picked him up as a stray)The shelter found him on 7/27/05, and I adopted him Aug 15th. I am assuming that he is now 5 months old. But he is much bigger than my friends cat which is supposed to be the same age. I know that different cats grow at different rates, and it is different between male and females. But he seems pretty big, I looks bigger than 6 months to me, but I could be mistaken. How can you tell the age of your cat, or is it just a guessing game?