How Old Is My Cat in "People Years?"

How Old is My Cat in "People Years?"

All my life, I've heard that one calendar year is equivalent to seven years in a dog's life. Not entirely accurate, but close enough. So what's the "standard" for cats? There's not really a simple answer to that, as no truly scientific method has been developed to gauge the maturity level of cats.

In actuality, cats don't age in a steady accumulation of time like humans do, but in a big spurt at the beginning of life, then more regularly as the years go by. And depending on your source, that growth rate differs. Knowing where your kitten is, developmentally, can help you with training and introducing kitty to new things. It also helps you know when your cat should be spayed or neutered to avoid any unwanted litters.

Understanding age equivalency as your cat ages can help you make adjustments to make kitty more comfortable and healthy. Senior cats experience more difficulty with their teeth and may have arthritis that makes moving around, or even bending down to eat, painful. Some also develop age-related diseases and they require more frequent check-ups at the vet.

I've combined information from several sites and compiled this Cat Age Chart to estimate your cat's age equivalent in human development and aging:

Cat's Age = Human Age 

(with outdoor cat's age in parentheses)

1 month = 5-6 months

2 months = 9-10 months

3 months = 2-4 years

4 months = 5-6 years

5 months = 8-9 years

6 months = 10-15 years

8 months = 15 years

1 year = 15-24 years

2 years = 24-28 years

3 years = 28-32 years (32)

4 years = 32-36 years (40)

5 years = 36-40 years (48)

6 years = 40-44 years (56)

7 years = 44-48 years (64)

8 years = 48-52 years (72)

9 years = 52-56 years (80)

10 years = 56-60 years (88)

11 years = 60-64 years (96)

12 years = 64-70 years (104)

13 years = 68-72 years (112)

14 years = 72-80 years (120)

15 years = 74-80 years

16 years = 76-84 years

17 years = 78-88 years

18 years = 80-92 years

19 years = 84-96 years

20 years = 96-100 years

21 years = 100-104 years

22 years = 104-108 years

23 years = 108-112 years

24 years = 112-116 years

25 years = 116-120 years

Cats mature quickly in their first year. After that, the level of development is more regular through the remainder of their life. But experts start referring to cats as "senior" at about the time humans would be middle-aged, about 7-8 years in the cat's life, and "geriatric" at about age 12. The oldest cat on record was Creme Puff, a female cat who died in 2005 at 38 years and 3 days old. Another cat in the UK is said to be 39 years old, placing her human age at around 172! Cat age calculators are available on a few sites, but it's not clear which model they're using to calculate the cats' ages.


An About.com entry includes the reminder that not all breeds of cats age at the same rate. Maine Coon cats, for example, develop more slowly and don't reach maturity until they're 3-4 years old. Just as with people's individual personalities, there is likely also some difference from cat to cat. Especially Cats points out that factors such as age of weaning, reproductive status, and the cat's genetic average mortality play a role in how fast a cat ages. And Catster reminds us that cats living outdoors will age more quickly, including a chart from The Cat Owner's Manual as backup. Those numbers are the ones shown in parentheses in the chart above.

Most of the charts stop at around 18-20 years of a cat's life, with only one going beyond. So it's hard to determine exactly how old my little Vixen, who had just turned 24 when she died last month, would have been in human years. Nearest I can guess, she would have been about 107-116 if she'd been a person. As more cats live into their 20s due to indoor living, better food and veterinary advances, it seems like some new charts need to be developed...and perhaps those designations of "senior" and "geriatric" need to be rethought, as well.


Sources for the chart above included CalculatorCat.com, The International Cat Agility Tournaments, About.com, Purina's UK division, Spoiled Kitty, Catster, and Cat Channel.

To help you address the needs of your cats at all ages, Old Maid Cat Lady has a special section for Kittens, and another for Senior Cats. Cats in between the two can use things from all the other products for cats categories!