How Does a Cat's Tail Relate to Its Size?

Your cat's tail helps him perform dizzying acrobats and clues you in to his mood, but it's got very little to do with how big he is or how big he'll grow. Some breeds have longer tails than others; other breeds have no tails at all.

  1. Skin & Bones

    • The average cat tail is nearly 10 inches for females and 11 inches for males. Most cats have at least 18 caudal (tail vertebrae) but some have as many as 28. The number varies by breed and genetic mutation. The average is 21 to 23, which accounts for about 10 percent of a cat's bones. Your cat's tail is essentially an extension of his spine. His caudal vertebrae house nerves that collect at the base of his tail, along with those related to his back legs and rear end. His tail muscles are related closely to the muscles that control those same body parts, too.

    Breeds Apart

    • Some cat breeds have longer tails than others, although that's not necessarily related to their size. Manx cats, for instance, are fairly large with longer rear legs, but have a dominant gene that makes them tailless. Other genetic lines, like that of the tailless Japanese Bobtail, are recessive. The vast majority of cats are domestic shorthairs -- the mutts of the cat world who carry genes from a variety of far-flung relatives. As such, a cat may have the body type or appearance of a specific breed of cat, but have a tail length associated commonly with another breed. Even within purebred cats, tail length can vary and has no relation to body size.

    Tall Tails

    • Your cat's tail may not tell you much about his size relative to other cats, but it's a great barometer for his mood. His tail includes voluntary muscles, so, yes, he's consciously controlling his tail, although some behaviors probably are instinctual. There are a few general rules when it comes to tails and feline body language. Heavy swishing or wagging means action; watch for an attack, play or otherwise. A straight, relaxed tail signifies affection, although a flipped tip isn't uncommon, either. A puffy tail, another sure sign of aggression, makes your cat look larger and more threatening, but don't confuse this artifice with his capacity for physical growth; the effect is temporary.

    Measurements

    • If you want to know how big your cat's going to be, you're better off reading a book, checking the Internet or talking with a vet than breaking out the measuring tape and trying to record the length of his tail. A number of cat fanciers' websites have breed profiles that yield general guidelines and averages. If you've got a domestic shorthair, though, there's no way to be sure what you and your cat are in store for. If you've got a kitten, it may be tempting to look at his paw size or tail length to approximate his eventual size, but there's no science to that. Instead, weigh him each week to make sure he's gaining weight at appropriate intervals. The scale, not the ruler, will be your guide.