How Old Is Your Cat in Human Years?

  • 01 of 07

    Conversion Chart of Cat Age to Human Age

    cat age to human age chart
    Illustration: Catherine Song. © The Spruce, 2018

    The International Cat Care organization has done the world of cats and their caregivers a huge service by reorganizing the chart showing comparative age of cats to human age.

    For many years the relative age comparisons previously used had only four age categories:

    1. Kitten: from birth to one year
    2. Adult: aka Maintenance years, from one year to ten
    3. Senior: from eleven to fourteen
    4. Geriatric: from fifteen upwards.

    International Cat Care has added two other life stages, which effectively "borrow" some time from one stage and add it to another:

    1. Kitten: from birth to six months
    2. Junior: from six months to two years
    3. Prime: from three years to six years
    4. Mature: from seven to ten years
    5. Senior: from eleven to fourteen years
    6. Geriatric: from fifteen years and older
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  • 02 of 07

    Kittens From Birth to Six Months

    Kitten on lap
    Fjola Dogg Thorvalds / Getty Images

    Jaspurr and his littermate brother, Joey, came to us from a home whose human was running an indiscriminate backyard breeding program with one aging whole female cat and a neighborhood of outdoor strays, also unneutered.

    Because we didn't want to take any chances of bringing infectious disease to our senior cat Bubba, we took the J-Boys to our veterinarian, Dr. Dietrich, the day after their adoption.

    They were then quarantined in our son's room until all the tests had come back negative, and they had their core vaccines at about nine weeks of age.

    This first life stage is the fastest for physical and social development than any other stage of a cat's life.

    Although Joey was the first kitten of their litter to be born, and Jaspurr was the last, Jaspurr was assertive from the start. It didn't take him long to be the alpha cat in their relationship, a distinction that he holds to this day.

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  • 03 of 07

    The New Cat Life Stage of Junior Makes Perfect Sense

    One year old happy cat laying in the park, Vietnam
    Pinnee / Getty Images

    For many years,  according to the original chart, we've been calling our kittens "adults" upon their first birthday. My two youngest cats, Sage and Gaither are well over one year old, and they don't yet act like adult cats.

    The thing is, that even though these year-old cats may appear to be adults physically, they are still developing mentally and emotionally. They still enjoy play, whether chasing one other,  or trotting after one of the older cats,  leaping around with a human wielding a feather wand, or just alone, happily rabbit-kicking a catnip-laced sock. Then, exhausted, they will crash, alone on the foot of a bed or head-to-toe on their huge beanbag chair, for a teen-age nap in the afternoon.

    Some cat breeds do not reach their full physical growth and development potential until around the ages of two to four.  The Maine Coon is one of these breeds, and my two tuxedo "brothers" both appear to have a strong Maine Coon factor in their genes.

    The Junior life stage designation lasts from six months to two years, and it fits both of these playful young cats perfectly. 

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  • 04 of 07

    Prime Cats - From Three to Six Years Old

    Maine Coon Cat Relaxing Indoors
    Purple Collar Pet Photography / Getty Images

    Franny's Note: As might be expected by the name, cats in their Prime years of three to six years, are in the prime of life. Newman, described here, is approximately 40 years old in human years.

    Six-year-old Newman is a certified, pre-owned, made-in-Michigan, gray-and-white, medium-hair male moggie love child. He began life in a private home but was given up to a small east-side-Detroit rescue group. We asked his foster mother for a calm cat who would be happy living with two empty nesters. We adopted him at age nine months.

    He has been the only cat in our home since his adoption. Newman is quiet, purring mostly when kneading on my wife. He spends most of his day sleeping and looking out the front window. When I get up, he gets a half dozen pieces of kibble as a reward for getting up with me But he has to wait for my wife to get up before he gets his first meal of wet food.

    At night, he sleeps with us or goes downstairs, or, usually, both. When I come home, he get a half dozen pieces of kibble for greeting me.

    Barry J.

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  • 05 of 07

    Mature Cats - From Seven to Ten Years Old

    Playful Tabby Cat Indoors
    Purple Collar Pet Photography / Getty Images

    It's hard to believe that our Jennifur is approximately 50 years old in human years. When we rescued her off the streets as a youngster, we had to "guesstimate" her age when we took her to our veterinarian for a checkup. Based on her assumed age then, she is as of this writing nine years old, and will be ten as of her "birthday" on July 4th, 2015.

    Mature is as mature does, and "Jenny" alternates between napping on my office bed as I work, and jumping to the back of my desk chair. Worse, she has taken lately to jumping on my keyboard when I leave the room, or batting the mouse off the desk.

    For the moment, Jenny is definitely not a "little ole' lady' cat, and she still has her "mojo".

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  • 06 of 07

    Senior Cats - From Eleven to Fourteen Years Old

    Our handsome boy, Billy will become eleven on March 5, 2015, and will join Jaspurr and Joey as senior cats. You would never recognize the sick, scrawny kitten we adopted when he was just five months old. Billy is the approximate equivalent of a sixty year old human - the time of life for humans and corresponding age of cats that certain medical problems arise, along with a decrease in physical activity.

    In Billy's case, he developed diabetes when he was about nine years old. So far, his diabetes has been controlled through diet, and there has been no need for insulin injections.

    Billy was also was diagnosed around the same time with hypertrophic cardiomyopathy, a condition for which there is yet no known cure. There are certain breeds of cats with genetic leanings toward this condition, including Norwegian Forest, (which Billy resembles,) and  Sphynx, Siberian, Ragdoll and Maine Coon cats. Another susceptible breed is the Devon Rex, Steve Dale's cat, Ricky, a Devon Rex, passed on from HCM at the age of two. Steve, along with the Winn Feline Foundation, established the Ricky Fund for research of HCM.

    My other two cats, Jaspurr and Joey, soon to be 13, have hyperthyroid disease, and hypothyroid disease. Their conditions are controlled by liquid medicine twice daily.

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  • 07 of 07

    Geriatric Cats - From Fifteen to Twenty-one and Older

    Eighteen Year Old Cat
    Maurice van der Velden / Getty Images

    As we learn more about the care and feeding of cats, they are living longer. Certainly, veterinary research has a bearing on our cats increased longevity. The three longest-lived cats in my family were Shannon and Arthur, who both lived to 19 and Bubba (pictured here), who survived to 18. All of them came to us as very young cats, and all of them had one or more chronic medical conditions toward the end of their lives.

    If any of my readers are thinking, "So what? Why should changing the name of a cat's life stage mean anything to me?"

    Consider this: If you understand that a kitten doesn't suddenly turn into an adult at the end of its first 12 months, you may not expect that "cat" to suddenly behave like a cat. You'll further understand why a Junior cat does not suddenly behave like a staid adult, and still needs interactive play as he did as a kitten. 

    Your increased understanding will affect your relationship with your cat(s), as you will react differently to their behavior, and your bond will grow even more.