How to Calculate Your Cat’s Age to Human Years


Many people mistakenly suppose that one cat year is equivalent to seven human years. But this isn’t actually the case – cats age differently than humans do, and the calculation isn’t quite so simple!

Sadly, our feline friends age much faster than us. But how do you accurately calculate your pet’s age? In this article, we’ll take a look at how to calculate cat years to human years.

How Much Are Cat Years to Human Years?

According to the American Animal Hospital Association (AAHA), these age guidelines have been created and agreed upon by the AAHA, the Feline Advisory Bureau (now known as International Cat Care), and the American Association of Feline Practitioners (AAFP):

  • The first year of a cat’s life is considered as 15 human years
  • The second year of a cat’s life is approximately 9 human years
  • Every additional year is equal to 4 human years

This means that when your cat is six years old its cat age to human years would be equivalent to 41 years.

Life Stage Cat Age Age in Human Years
Kitten 1 Month 1
3 Months 4
6 Months 10
Junior 12 Months 15
18 Months 21
2 Years 24
Adult 3 & Up 28 + 4 for every additional cat year
Senior  11 & Up 60 + 4 for every additional cat year
DID YOU KNOW: The world’s oldest cat was 38 years and 3 days old according to the Guinness World Records.

Do Indoor and Outdoor Cats Age the Same Way?

A cat parent’s biggest dilemma is whether there are any differences in the aging process between indoor and outdoor cats. The topic still remains controversial and there is a rationale behind both sides of the argument. According to the AAHA, outdoor cats age much faster than indoor cats. Typically, indoor and outdoor cats’ age in cat years is different even if they are of the same breed.

Indoor cats are less likely to experience trauma (except separation anxiety) and diseases. Indoor cats live the best life, served with the best senior food and receiving constant love and affection. They typically don’t experience the same hazards as outdoor cats, and they’re also less likely to get parasites or succumb to predators.

Outdoor cats are more likely to suffer from injuries and diseases, as they lead a harsh life. They endure all four seasons, exposed to intense cold and heat. However, the indoor cat’s life often leads to obesity and other health problems related to insufficient physical activity.

Some people let their cats outside, some keep them inside. It is up to each cat parent to choose what is best for their cat. But it is worth noting that this choice might have an impact on how you’ll calculate human years to cat years.

Signs Your Cat Is Getting Old?

As cats age, there are typically some physical and behavioral markers that show that they’re getting older. Here are some of the feline signs of aging:


As cats get older, their teeth can turn yellow and plaque can build up, leading to dental problems. If you notice yellow stains on your cat’s teeth, it means that the cat is growing old. Tartar build-up is very common in cats over the age of 2. We already know that two cat years compared to human years is 24, therefore it’s completely normal for tartar build-up to appear. The greatest indicator that your cat is at its senior life stage is missing teeth. Cats’ teeth tend to fall out with age.


Another key indicator of aging in cats is their coat. As they grow older, cats’ fur may become thinner, patchier, and less lustrous. In addition, senior cats may start to groom themselves less often than they did when they were younger. As they get older they may have patches of graying fur and white marks.

Activity Level

A lower activity level is another clue that your cat is getting older. Three human to cat years is 28. Even when we, humans, reach 28 we tend to become less active than we used to be and feel like we want to relax after a long day of work. Older cats sleep more and are less active than younger ones. You might notice a change in their muscle structure, as they become bonnier with age. However, it’s important to keep in mind that these changes can vary from cat to cat – some senior cats may still be very active, while others might be less so.

Behavioral Changes

Other signs of the cat’s aging process that will help when you want cat years compared to human years include its behavior. As cats age, they may start to behave differently than they did when they were younger. For example, older cats may become less sociable, or be more anxious than before and spend more time alone. If you notice that your cat is suffering from anxiety, try using a pet-approved CBD oil. They might also start to urinate or defecate outside the litter box or become more vocal.

If you’re not sure how old your cat is, you can always turn to veterinarians for the cat’s stages of growth and development. They should be able to give you an estimate from cat to human years based on your cat’s physical appearance and health history.

DID YOU KNOW: If you want to engage your indoor cat with the outside world while still keeping it secure, consider constructing an outdoor cat enclosure. This will allow it to enjoy the outdoors safely. 

Why Is It Important to Know Your Cat’s Age?

Generally speaking, cats live longer than dogs – their average lifespan is around 20 years. But why is it important to know how to convert cat years to human years?

Knowing your cat’s age is important for a number of reasons. For one, if you know your cat’s age, you will pay more attention to detecting health problems cats are prone to such as diabetes or kidney failure. The moment you notice some changes in their behavior it’s best to check with your vet and get the treatment they need as soon as possible. If the disease is already advanced, you may even need to consider euthanizing it.

It also enables you to provide appropriate care and accommodations for your elderly pet. Most importantly, being aware of your pet’s age helps you to cherish every moment you have with your furry friend.

Key Takeaways

Two cats to human years are approximately 24 years.
If you are wondering whether there are any differences between outdoor and indoor cats in regard to their aging, they undergo quite different aging processes.
The changes in the cat’s teeth, coat, activity levels, and behavior are signs that your cat is growing old.
It’s important to know your cat’s age because with age your cat becomes more prone to diseases.

Wrap Up

Understanding how to calculate cat years to human age is important for all cat owners. While the average conversion is four cat years for every human year, there are many variables that can affect a cat’s lifespan. These include diet, lifestyle, genetics, and whether or not they are spayed or neutered. Keep an eye out for the key signs of old age in your cat, and if you have any questions or concerns, be sure to consult with your vet.


How many cat years is one human year?

A cat reaches the equivalent of one human year when it is only one month old.

How many years does a cat live?

On average, the life expectancy of a cat is around 20 years. However, this number can vary widely depending on a number of factors such as diet, lifestyle, and genetics.

Are cat years the same as dog years?

No, cat years and dog years are not the same. In general, cats live longer than dogs do. On average, a cat lives around 20 years as opposed to around 12-13 years for dogs.

This means that the conversion from cat years to human years is different from the conversion from dog years to human years.


When she couldn’t decide between being a nurse, a psychotherapist, and a financial genius, Ofelia decided to do all three. Her interests run far and wide, and she loves researching about everything you get to read on our website. Credit cards or top-notch software, she’s here to tell it all like it is.

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