Cat Years to Human Years Calculator

Danielle Petch
A birman cat looking at the camera

“How old is my cat in human years?” It’s a question every cat owner has asked themselves at one point or another.

You’ve probably heard that one cat year = seven human years, but you may be surprised to learn that that’s not strictly true! So, how do you calculate cat years to human years? Luckily, there’s a handy cat age calculator to help you crunch the kibble (sorry, numbers)…

How to convert cat years to human years

While there’s no real scientific way to calculate cat years to human years, the idea that one cat year = seven human years is a widely believed misconception. According to the American Animal Hospital Association (AAHA), you can determine your cat’s age can using the following metrics:

  • 1st year of a cat’s life = 15 human years
  • The second year of a cat’s life = an additional nine years
  • Every subsequent year = equivalent to four human years

Yes, your adorable, goofy kitten is already a teenager! In human years, at least. 

According to AAHA’s guidelines, by the time your kitty is two years old they are already about 24 years old in human years. These guidelines are based on both the physical and behavioural stages of a cat’s life, which are then matched to similar stages of a human's life.

In a similar vein, a senior cat of around 15 years of age could actually be the equivalent of 76 human years! 

Take a look at our handy ‘cat years to human years’ comparison chart below to find out how old your precious puss is...

Source: AAFP–AAHA Feline Life Stage Guidelines

How do cats age?

Cats generally age quite quickly at the beginning of their life, and the older they get, the slower the ageing process becomes. 

While there will be some variation in these calculations based on your cat, their breed and their environment, it's pretty simple to calculate a cat’s age to human years (at least compared to calculating a dog's age to human years, which can vary greatly depending on breed and the size of the dog).

The great news is that thanks to better nutrition and vet care, our cats are living longer than ever! This has led to the various life stages of a cat being refined in recent years. According to International Cat Care, cats are now considered to be “elderly” or “senior” once they reach 11 years old, with “senior” cats sitting in the 11-14 age bracket. And if you’ve got a 15+ year old cat in your household, then congrats! You’ve got yourself a loving and loyal "geriatric" cat.

How can I tell how old my cat is?

Unless you've had your kitty since the day it was born, the truth is, we don’t always know exactly how old our cats are. 

Your vet will be best placed to determine the age of your cat, but there are some telltale signs you can probably spot already to help guesstimate your cat’s age:

  • Teeth: while dental problems can be hereditary, they can also be a sign of age. A kitten will usually get its milk teeth at around 2 to 4 weeks, and its permanent teeth should come in by the time they are 3 to 4 months. Yellowing teeth can be a sign of ageing and this could begin as early as 1 year old, while missing teeth may suggest an older feline, of at least 10 years plus. 
  • Coat: kittens begin with soft, fuzzy fur, but as they age this inevitably changes. Older cats will typically have thicker, coarser fur, and you may even notice patches of lighter coloured hair in senior cats (similar to how we humans go grey as we age). Grooming is another telltale sign, as typically, senior cats may not groom themselves as much or as regularly as they did in their younger days.
  • Eyes: they say eyes are the windows to the soul, but in this case, they can also be a great indicator of your cat’s age! While young cats and kittens will have bright and clear eyes (providing they are in full health), by the time a cat reaches around 10 years of age, you may begin to notice cloudy and/or teary eyes. 

A hand lightly tapping a cat's nose

Do all cats age the same?

Of course, not all cats age alike! And when working out cat years to human years, one thing to keep in mind is your cat’s lifestyle. 

While our feline friends will typically live 10-15 years on average, this can vary by breed, and according to the AAHA, whether your cat is indoor-only (or whether they have an indoor/outdoor lifestyle) can also affect the way they age.  

While an indoor-only lifestyle can increase your cat’s lifespan (through the decreased risk of trauma and infectious disease), it may also increase the risks of other illness, due to various environmental limitations.

On the flip side, while an indoor/outdoor lifestyle may provide a more "natural" environment for cats, it may well increase the risks of infectious disease and potential trauma.

Caring for your cat at every stage

As cats age, their needs, personality and temperament can change. From kittenhood to senior status, it's important to know how to care for your cat at every stage of its life, to ensure your kitty is getting the love, care and attention it deserves (and often, demands...)

One thing that we can all agree on is that our precious felines are adorable, whatever their age! We hope you enjoyed our “cat years to human years” calculator, and don’t forget — you can find even more answers to common kitty queries on our blog, so be sure to have a paw around.

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