# How to calculate a cat’s age in human years

*What does your cat’s age really mean?*

Comparing your cat’s age to the equivalent in «human years» can help you get some perspective on your cat’s stage of life. Understanding the feline aging process will help you care for your cat as experiences the challenges of growing older.

Instructions

## Make your best guess at your cat’s true chronological age

If you adopted your cat from a shelter or found him as a stray, then you may not have an exact value. Your vetrinarian will be able to make an educated guess at your cat’s age based on some physical characteristics.

## If your cat is between 1 and 2 years old…

Take your cat’s age in months and subtract 12. Multiply that number by 3 and then divide the result by 4. Add 15 to that number, and you have your cat’s age in «human years».

For example, if you have a 17 month old kitten, you would subtract 12, which gives you 5. Multiplying 5 X 3 gives 15, which we now divide by 4 to get 3.75. Finally, we add 15 to 3.75 and get 18.75.

Your 17 month old «kitten» is actually a «young adult,» but at least she won’t head off to college and only call when she needs money for «books».

## If your cat is more than two years old…

Take your cat’s age in *years* (not months) and subtract 2. Multiply the result by 4, and then add 24 to get your cat’s age in «human years».

For example, if you have a seven year old cat, you would subtract 2 from 7, which gives 5. Multiplying by 4 results in 20. Finally, we add 24 and see that the cat is 44 «human years old».

Your 7 year old cat is approaching middle age and may not be as playful as he was when he was younger. You may need to change his diet to compensate for reduced activity and slowing metabolism, and your vet may have other age-related advice for your cat.

**You will Need****Tips and warnings**

**Category:**

Hi, Molly. That’s a good question. To write the how-to, I used the table that is the first link under the heading «Cat Years Charts». I assumed that the cat’s «human years» age is a piecewise linear function of chronological age, i.e. that each stage of the cat’s life can be described by a straight line. It’s only a rough guide; no formula will fit all cats, but it will give a good perspective on the life stage of your cat.

That’s an interesting formula for figuring a cat’s age. Can you please provide the source?

Hi, Molly. That’s a good question. To write the how-to, I used the table that is the first link under the heading «Cat Years Charts». I assumed that the cat’s «human years» age is a piecewise linear function of chronological age, i.e. that each stage of the cat’s life can be described by a straight line. It’s only a rough guide; no formula will fit all cats, but it will give a good perspective on the life stage of your cat.

That’s an interesting formula for figuring a cat’s age. Can you please provide the source?

Hi, Molly. That’s a good question. To write the how-to, I used the table that is the first link under the heading «Cat Years Charts». I assumed that the cat’s «human years» age is a piecewise linear function of chronological age, i.e. that each stage of the cat’s life can be described by a straight line. It’s only a rough guide; no formula will fit all cats, but it will give a good perspective on the life stage of your cat.

That’s an interesting formula for figuring a cat’s age. Can you please provide the source?