People often say that one human year is the equivalent of seven ‘cat years’, but in reality a one-year-old cat is much more mature than a seven-year-old child, cats actually age must faster than that. And with age, we know that diseases often follow, but cats also act differently at certain life stages. Because of these things, it’s not only helpful, but also important to be able to understand what your cat is going through at each stage of life.

Determine how old your cat is

If you got the kitten from a breeder, you may know exactly how old your cat is, but if you adopted the cat whose age is unknown, there are some ways to determine her age in cat years. Here are some things vets check to get a general sense of how old a cat is in cat years:

  1. A Cat’s Teeth: Teeth are a great indicator of a cat’s age in cat years. Older cats tend to have more staining than younger cats, assuming the previous owner was negligent in brushing the cat’s teeth. And a kitten’s teeth first come in between two to four weeks; their more permanent set appears at around four months of age. So if you open a cat’s mouth and find permanent, white teeth, the feline is likely to be around a year old. Some yellowing might place the cat between 1 and 2, and tartar build-up on all the teeth indicates that the cat could be between 3 and 5. Missing teeth may mean you have a senior cat on your hands.
  2. A Cat’s Muscle Tone: Younger cats are more likely to have some muscle definition from their higher activity level. Older cats are usually a bit bonier and may have some extra skin hanging or protruding shoulder blades.
  3. A Cat’s Coat: The condition of a cat’s coat is another great indicator of a kitty’s age in cat years. Kittens and younger cats usually have soft, fine coats, whereas older cats tends to have thicker, coarser fur. A senior cat may display grays or patches of white.
  4. A Cat’s Eyes: Bright, clear eyes without tearing or eye discharge are common in younger cats. A cat with some cloudiness in their eyes is likely to be 12 years old or so. While inspecting the lens, also examine the iris of the eye. Young cats have smooth irises, while the iris of an old cat can sometimes appear somewhat jagged.

Converting to human years

If your cat is a brand new kitten, snuggle her tight because within the first year she will be a teenager!  A cat is approximately 15 human years after her first year, then 24 human years by the age of 2 (see chart below)! 

Cat Age ( years) Human Age (years)

  • 1-month-old kitten is age in 6-month-old in human years.
  • 3-month-old kitten is age 4 in human years.
  • 6-month-old kitten is age 10 in human years.
  • 8-month-old kitten is age 13 in human years.
  • 1-year-old cat is age 15 in human years.
  • 2-year-old cat is age 24 in human years.
  • 3-year-old cat is age 28 in human years
  • 4-year-old cat is age 32 in human years
  • 5-year-old cat is age 36 in human years
  • 6-year-old cat is age 40 in human years
  • 7-year-old cat is age 44 in human years
  • 8-year-old cat is age 48 in human years
  • 9-year-old cat is age 52 in human years
  • 10-year-old cat is age 56 in human years
  • 11-year-old cat is age 60 in human years
  • 12-year-old cat is age 64 in human years
  • 13-year-old cat is age 68 in human years
  • 14-year-old cat is age 72 in human years
  • 15-year-old cat is age 76 in human years
  • 16-year-old cat is age 80 in human years
  • 17-year-old cat is age 84 in human years
  • 18-year-old cat is age 88 in human years

How long do cats live?

Felines are generally quite long-lived, though mileage varies depending on owner maintenance and genetic predisposition. In a handful of documented cases, cats have exceeded 30 years in age. Typically, indoor cats may live 12 to 18 years, with many surviving into their 20s. However, one thing to bear in mind, outdoor cats can have a significantly shorter life expectancy then indoor-only cats, often living only two to five years. Pet parents in urban and suburban areas are strongly encouraged to keep their cats indoors.