Updated - Mar 29th, 2023
- The common “one cat year equals seven human years” rule is a myth.
- The first year of a cat’s life is equal to 15 human years, while the second year is equal to an additional nine years. After the second year of a cat’s life, each additional year is equal to about four human years.
- Cats grow quickly in their first two years of life, and then more slowly and steadily after that. They can live to be anywhere from 20 to 25 years old.
You’ve probably heard the saying that one year of a cat’s life is equal to seven human years.
It may surprise you to learn, however, that this is a myth! So you may be wondering, why is this “rule” such common knowledge?
Generally, it’s thought that the “one year to seven years” calculation for both cat years and dog years was created to simply demonstrate that our pets age much faster than we do.
When it comes to cats, however, our feline friends actually age much faster than you might expect. How do you accurately calculate your cat’s age to human years?
Let’s dig in…
How do I calculate my cat’s age in human years?
So, if you’re asking – “How old is my cat in human years?” – 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.
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 equal to approximately 15 human years.
- The second year of a cat’s life is equal to an additional nine years.
- 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 chart below to find out!
Cat years to human years chart
|Cat Age||Human Age|
|1 month||1 year old|
|3 months||4 year old|
|6 months||10 year old|
|12 months||15 year old|
|18 months||21 year old|
|2 years||24 year old|
|3 – 10 years||28 year old +4 for each cat year|
|11 years and older||60 year old +4 for each cat year|
How do cats age?
As you can see, the common 1:7 ratio is very misleading – cats age much more quickly in their first two years of life and then the aging process slows down and continues more steadily after that.
How did veterinarians settle on this cat age to human age calculation?
When it comes down to it, the AAHA states that their guidelines are based on the physical and behavioral changes that occur at different stages of a cat’s life – and then these stages are matched to stages of human life.
In other words, a one-year-old cat is physiologically similar to a 15-year-old human – in their own respective ways, both the cat and the human are at similar stages of growth and development.
Of course, as with humans (and dogs for that matter), there will be some variation in the way your individual cat ages. But unlike dogs, there seems to be much less variation with different cat breeds and the way they age. With dogs, you’re much more likely to see smaller breeds live longer. Even when we look at cats by breed, the variations don’t seem large enough to contribute to these kinds of age differences.
Do indoor and outdoor cats age the same way?
Another factor that may play a role in how cats age is whether they’re indoor or indoor-outdoor cats. In fact, the AAHA actually states that this is a controversial topic and there is valid rationale behind both sides of the argument.
According to the AAHA, indoor cats are less likely to experience trauma and exposure to certain infectious diseases which may result in longer lifespans. On the other hand, indoor cats may be at a greater risk for illness due to environmental limitations.
For outdoor cats, the reverse is true. Although outdoor cats can benefit from a natural and stimulating environment, they’re at a much greater risk for trauma and exposure to disease.
Ultimately, it’s up to each cat parent to decide which of these lifestyle options works best for their cat, but it’s worth noting that this decision may contribute to the way your cat ages.
What are the signs of a senior cat?
With this in mind, there are some physical indicators that can help you get a sense of your own cat’s age, particularly as your adult cat reaches their senior life stage.
- Teeth: Yellow stains and tartar build-up, missing teeth
- Coat: Graying fur, as well as thicker, coarser fur in comparison to young cats
- Eyes: Cloudiness, tearing, and discharge
- Activity level: Less activity, weight or muscle loss (becoming bonier), arthritis is also more common
- Behavioral changes: More meowing, more wandering around, increased level of anxiety, confusion or disorientation
If you’re unsure how old your cat is, you can always turn to your veterinarian for more information. Your vet will be able to use physical and behavioral markers to help make the best estimate of your cat’s age.
Why is understanding my cat’s age important?
Now that you know how to properly calculate your cat’s age into human years, you might be wondering: How long do cats live? What is the life expectancy of my cat?
Generally, cats are known to live longer than dogs – they can live anywhere from 20 to 25 years. In fact, according to the Guinness Book of World Records, the “oldest cat ever” lived to be 38 years and 3 days old, which is 168 in human years!
Like dogs, however, once cats reach seven to 10 years old, they start to transition into their mature years. Knowing that they’ve entered this life stage is important, so you can know how best to care for them. During this time – from seven to 10 years old – you’ll want to keep a closer eye on your cat for signs of aging, especially since older cats are more likely to develop diseases like cancer, arthritis, and heart, kidney, and liver disease.
It is also worth noting that while most dogs are considered “senior” at around seven years old, the AAFP designates cats ages seven through 10 as “mature” or “middle-aged,” and “senior” once they reach 11 years old. Cats are considered “senior” until age 14; from age 15 and on, the AAFP considers them “geriatric.”In general, helping your cat maintain a healthy diet, weight, and receive regular check-ups at the vet will help give them the best possible chance of living a long and healthy life!
Additionally, you might consider investing in pet insurance to cover any unexpected accidents or illnesses. After all, your cat deserves the best care possible no matter how old they are – this is why Pumpkin insures cats of all ages!
The bottom line
At the end of the day, cats age much more quickly during their early years than most people think – by the age of two, your cat is 24 years old in human years! Luckily, after the age of two, it’s pretty simple to calculate your cat’s age in human years – you simply have to add four for every additional year. You can also always refer to our cat age to human years chart (or even print it out!) to quickly determine how old (and wise, of course) your favorite feline really is.