How Old Your Cat Is In Human Years

Transferring cat years into human years is a tricky endeavor. Scientists have come up with a formula that gives us an approximate guess of a cat's age in human years. And while you've probably been told all your life than one cat (or dog) year is equivalent to seven human years, the reality is a bit more complicated than that. While cats do age much faster than humans, they don't age in exact increments of seven years every 12 months.

According to Science Magazine, our pets are living longer than ever. As cats have become indoor-only beasts with better diets and better access to healthcare, their life expectancy has doubled. In fact, studies show that the average cat in the U.S. has now a life expectancy of 15 years, while just a few decades ago, the average lifespan was under 10 (via The Cut).

In case you were wondering, kitty's wild cousins have similar lifespans. In the wild, a lion has an average lifespan of about 15 years; in captivity, the number jumps to close to 30. As is the case with stray and feral cats, lack of medical care in the wild means even a small injury can turn deadly (via Zoological Society of London).

According to tables created by the experts, including the American Animal Hospital Association (AAHA), cats age particularly fast during the first year of their life. In fact, by the time your cat turns 6 months old, he's already the equivalent of 10 years old in human years. By 12 months of age, he's a 15-year-old teenager.

Things slow down after that. During the second year of his life, your cat will only get nine years older, instead of 15. After that, each year of your cat's life is the equivalent to four human years. So your 2-year-old cat is the equivalent to a 24-year-old human, and a three-year-old cat is 28.

Cats become seniors around the age of 11, which would be about 60 years old in human years. This is slightly older than dogs, who become seniors at anytime between 7 and 10 years old, depending on their breed and size (the bigger the dog, the sooner they are considered seniors). After the age of 15, cats become "geriatric" — a step older than "senior." By this time, they're already the equivalent to a 76-year-old human.

It's not that rare for cats, however, to live longer than that. In fact, the AAHA has posted an age table for cats that goes up to age 25, which means it's not that rare for cats to reach the equivalent of 116 years old in human years.

According to Guinness World Records, the oldest cat to ever live was Creme Puff. He was born in 1967 and lived in Austin, Texas until his death 38 years and three days later. Since the American Association of Feline Practitioners designates cats over 15 as geriatric, Crème Puff was certainly a very, very old kitty. In fact, based on chart calculations, he was the equivalent of 168 human years when he died.

He's not the only very old cat to ever live. Creme Puff's owner previously shared his life with another senior feline, Grandpa Rex Allen, who lived to be 34 years old (via Life With Cats).

Although both these cats were the equivalent to "mutts" (mixes), some cat breeds are more likely to live longer than others. Siamese, Burmese and Balinese cats all seem to live longer lives, often into their 20s (per the Martha Stewart website). If you're keeping track, that means many cats now make it to the human equivalent of their 100th birthday – not a bad deal at all.