A question often asked by cat owners when trying to decide if their pet pussy is young, middle-aged or just plain’over the hill’.

The calculation is fairly simple. Compared to dogs, which have greater variation based on size and breed, the method to calculate a cat’s age is pretty standard.

The Rules to calculate your cat’s age are :

  1. Year 1 of a cat’s life is equal to approximately 15 human years.
  2. Year 2 of a cat’s life is equal to an additional nine years.
  3. After the second year of a cat’s life, each additional year is equal to about four human years.

So, how old is your cat in human years? You can use our cat age to human years chart below to find out!

Life StageCat AgeAge in Human Years

1 month1
3 months4
6 months10

12 months15
18 months21
2 yrs24

3 yrs & up28
+4 for every additional cat year

11 yrs & up60
+4 for every additional cat year

The above age guidelines were created and agreed upon the American Animal Hospital Association (AAHA), the Feline Advisory Bureau (now known as International Cat Care), and the American Association of Feline Practitioners (AAFP). So now you know!

As you can see, the common oft quoted 1:7 ratio is very misleading – cats age much more quickly in their first 2 years of life and then the aging process slows down and continues more steadily after that.