An older woman cuddling an older senior black cat.
An older woman cuddling an older senior black cat. Photography © GrapeImages | E+ / Getty Images Plus.

How to Calculate Cat Years to Human Years

One cat year does not equal seven human years. Read on for tips on determining your cat’s age and check out a helpful cat years to human years chart.

A popular misconception is that cats age seven years (in human years) for each calendar year. In fact, feline aging is much more rapid during the first two years of life. A cat reaches the approximate human age of 15 during his first year, then 24 at age 2. Each year thereafter, a cat ages approximately four cat years for every calendar year. Thus, a cat who is 5 in cat years would be approximately 36 in human years.

Note: It should be remembered that a cat who lives outdoors ages far more quickly, perhaps even twice as fast, than an indoor cat. Scroll to the bottom of this article to find out more about cat to human years for outdoor cats.

Indicators of a Cat’s Age

If you’ve taken in a stray cat or adopted a 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:

  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.

A Cat’s Life Span

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.

Outdoor Cats Life Expectancy — How Long Do Outdoor Cats Live, in Cat Years?

Outdoor cats can have a significantly shorter life span 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.

Tell us: How old is your cat in cat years? How old is your cat in human years?

Top Photo: © GrapeImages | E+ / Getty Images Plus.

This piece was originally published in 2017. 

Read Next: The Golden Years – When Your Cat is 15

182 thoughts on “How to Calculate Cat Years to Human Years”

  1. Joanne Umbrasas

    My Simon is a 20 (human years) old barn cat. He’s extremely fit and healthy. That’s 96 according to the calculation provided.

  2. My cat Frankie is one and half years old she was born on the 8th March 2019 so i guess now she is about 19 in cat years i think ?
    My late cat Oscar died in July 2018 he was only twelve in human years he had kidney problems which led to kidney failure he was put to sleep on the 20th July 2018 the day after my birthday .Oscar followed me every where sat with me slept with me i miss him so much i didn’t think i could love another cat but ido Frankie is a amazing cat to let me know she wants to go out at night time she jumps from side table on to me in bed and keeps doing it till i get up and let her out and then i wait in the kitchen for her to come in again then go back to bed.

  3. Florence Sdanowich

    I recently had to put down my domestic ndoor male cat M&M he was diagnosed with stomach cancer and it was too late to do chemo. His sister Spookie and I am mourning over him. She sits next to M&M’s cremation box waiting for him to come out. They were born 9 years ago in my yard in the shelter I had for the outdoor cats. Do you think it is from the wet cat food? They only ate Friskies. He had been so active and all of as unden stopped eating and drinking and Itook him to the Vet and was told he was too dehydrated and week to survive chemo. The Vet wanted to put him down and said he would last about 3 days. I got some medication for him and Pate food and he hung in there for me for more than a month. Miss him SOOO much.

  4. Persephonie Chavez

    My two cats are 3 months old in human years. How old are they in cat years?, so I can keep track from here on out. It would really help.

  5. We have a cat year’s chart that we got some time ago, it has this web site on it and I was
    wanting to find it here but I can not find it anywhere on your web site. Can you help
    me? It has at the bottom ” Illustration from the cat owner’s manual “

  6. Claire Drouault

    My cat is indoor/outdoor. She turned 13 last month. She has a cat door but lately spends most of her time indoors. Mornings and evenings she goes outside. She catches chipmunks when they’re in season, brings them inside for her dog to kill, and then eats her favorite parts.

    1. I have three indoor cats. The eldest is male 17 years, he still plays like a kitten, but sleeps more than he used to. He also does not see as well out of his left eye, other than that, he is in good health. Our next is a 9 years old male. Our female just turned 2 years of age. They all are tuxedo breed. My husband and I have always believed, life is better with a cat.

  7. Pingback: How Old Is My Cat? 4 Helpful Signs Vets Look For – Cat Zoomies

  8. Geoff Greening

    My cat is 21 human years old…still looks like a kitten missing only one bottom “fang” and can still jump through a 4 1\2 foot high window. My question is how old is she in cat years?

  9. I had 3 cats who were related and each lived to be 22 years old. I now have a cat who will be 16.5 years old on July 4, 2020. I always show only love to my cats and allow them to live life on their terns.

  10. I have had a stray cat ???? for 5 years.
    She is going grey around her mouth.
    Don’t know how old she is or was when I got her.

  11. Pingback: Πώς να υπολογίσετε τα χρόνια της γάτας σε ανθρώπινα χρόνια – Socialize my Pet

  12. Pingback: How to Calculate Cat Years to Human Years – Growing Social

  13. My oldest cat just turned 16 on April 24, 2020, or 80 in cat years! ????

    The middle one will be 14 in September, or 72 in cat years!????

    The youngest will be 12 also in September, or 64 in cat years!????

    1. Those aren’t supposed to be question marks, I posted heart emojis & apparently that’s how it came out LOL oops! ;)

  14. My stray is approximately 3years old. Because of her being abandoned she lost 12 teeth and her hearing from a severe infection. How old is she?

  15. I’ve always thought that the seven-to-one age ratio was for dogs. I’ve never heard of it for cats. (It’s not true for dogs, either.) The second year of a cat’s age is the equivalent of 24 human years. Every year after that, from Year Three and beyond, is equal to four (4) human years. Therefore, a five-year-old cat is equal, agewise, to a 39-year-old human (24+15). A 12-year-old cat is equal to a 64-year-old human, etc.

  16. My cat just turned 10 how old is he in hiumab years as he has cancer and there’s nothing we can do now as it’s metasitsized

  17. Pingback: How Long Do Cats Live? Facts About the Average Cat Lifespan

  18. Pingback: How Much Should I Feed My Cat? – BESTOFEASYLIFE

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