Deciphering Cat Ages & Stages

Of all the myths involving companion animals, one that continues to persist (and still drives me batty) is the notion that cats (and dogs) grow older at a pace of seven years for every human year.

Frankly, this idea has never made much sense to me. We’ve all seen (or at least know of) cats who have lived to the age of 20. In fact, at one point I had over 30 20-year-old cats in my veterinary practice. Using the 1-equals-7 rule, a 20-year-old cat would be the equivalent of a 140-year-old person, which simply isn’t possible. Let’s now consider reproduction. Cats and dogs can get pregnant and produce offspring as early as 6 months of age. Using the 1-equals-7 rule, a 6-month-old cat is equivalent to a 3½-year-old human. Can people have babies at this age? Of course not! The 1-equals-7 rule doesn’t work for the simple reason that cats age faster when they’re younger and slow down when they’re older.

How to compare cat years to human years

A number of years ago, the American Association of Feline Practitioners (AAFP) and the American Animal Hospital Association (AAHA) collaborated to create an age-comparison chart that takes this into account. (See sidebar.) According to this chart, a 1-year-old cat is equivalent to a 15-year-old person, and a 2-year-old cat is like a 24-year-old person. After that, you add four human years for every cat year. This is a more logical approach and, in my experience, it seems pretty accurate. Note: This chart doesn’t apply to dogs. Dogs have different age equivalents depending on their size (big dogs have shorter life spans than small dogs, for example). Cats are all roughly the same size, so the chart is universal for cats.

How many life stages do cats have?

Another topic related to age and longevity is cat life stages. There are several opinions on this subject but no consensus. The variations are mostly based on semantics, and whether you tend to be a “lumper” or a “splitter.” Lumpers prefer to group some stages together into a larger category, while splitters prefer to subdivide the stages. The only common ground among all the versions is the first life stage: kitten.

The updated age-comparison chart mentioned above also describes the life stages of a cat, dividing it into six distinct stages:

Kitten: 0 to 6 months

Junior: 7 months to 2 years

Prime: 3 to 6 years

Mature: 7 to 10 years

Senior: 11 to 14 years

Geriatric: 15 years and older

Splitters were probably happy with this six-stage version, although as a cat veterinarian, I had mixed feelings. I never knew exactly where to draw the line between “adult” and “senior.” Dividing older cats into “mature,” “senior” and “geriatric” categories based on these age ranges seemed sensible. However, dividing younger adult cats into “junior” and “prime” felt a bit contrived.

In a recently updated (2021) report, the AAFP/AAHA described four basic age-related feline life stages:

Kitten: birth to 1 year

Young adult: 1 to 6 years

Mature adult: 7 to 10 years

Senior: Older than 10 years

If you’re a lumper, you probably love this streamlined version. I’m content with the first three categories and their associated age ranges; however, I feel that the senior stage should be further divided, resulting in a five-stage classification that, in my opinion, covers all the bases:

Kitten: birth to 1 year

Young adult: 1 to 6 years

Mature adult: 7 to 10 years

Senior: 11 to 15 years

Geriatric: 16 years and older

I’ve seen variations of the versions described above, but with the term “super senior” replacing the term “geriatric.” I suspect some people feel that the word geriatric is too clinical, or that it carries negative connotations. As a veterinarian, I prefer the term geriatric, although I understand why cat parents would fancy the term super senior, as it invokes awe and wonder and makes the cat sound like a superhero, which is a pretty cool concept.

Finding the right care for your cat at each stage

The main reason veterinarians divide a cat’s life into stages is to help us formulate health and wellness plans that are appropriate for that particular life stage. The illnesses and behavioral changes we’re likely to encounter, and the diagnostic tests that are recommended, will differ depending on these stages. Whether you, as a cat parent, prefer the four-stage classification (kitten, young adult, mature adult, senior), a five-stage version (kitten, young adult, mature adult, senior, geriatric) or a six-stage model (kitten, junior, prime, mature, senior, geriatric) is a matter of personal preference. As a cat veterinarian who feels that all cats die too young, the fact that so many life stage charts recognize the existence of a geriatric or super senior stage tells us that cats are living longer than ever before, and that’s something we can all agree is wonderful news.