Instructions
Wait until your cat is six to 10 weeks old. Kittens do not have visible testicles as dogs and other animals do, so in order to view them, you must wait until the animal is at least six weeks old.
Lift the cat's tail. Once the cat has reached six to eight weeks old, the cat will have two visible openings beneath the tail; the anus and an opening for the penis or vagina.
Determine if the cat is male or female. If the cat's anus and the second opening are more than 1/2 inch apart, and the second opening appears to be in the shape of a hole rather than a slit, the cat is a male. If the cat's anus and the second opening are very close together, and the second opening looks more like a slit rather than a hole, the cat is a female.
Check to see if the cat is neutered. A neutered male cat looks very similar to a female cat, so checking to see if it is neutered can help verify that you haven't mixed up the sex of the cat. Adult male cats are missing their testicles and look very similar to female cats. A neutered male cat will have spacing that is more than 1 inch apart between the anus and the second opening. The anus and vaginal opening of a female cat are less than 1/2 inch apart.
How to Know if Your Cat Is a Male or Female
Determining the sex of a cat is not as straightforward as it is with other animals such as dogs. In fact, it is nearly impossible to determine the sex of a kitten, so you must wait until the animal is about two months old. You can figure out a cat's sex by checking the spacing and size of its genitalia, which is located beneath the anus.