Cat Years Calculator & Chart: Your Cat's Age in Human Years

According to popular legend, one human year is the equivalent of seven ‘cat years’, but in reality, a one-year-old cat is much more mature than a seven-year-old child. Learn all about your cat’s lifespan and approximately how old they are in human years in this guide.

What is a cat year?

Differing with each age, cats have a shorter lifespan than we do and so their years are equivalent to many human years. If we want to compare, we can work out cat years to human years with simple maths. Knowing  our cat’s age helps us allows us understand  their maturity and their needs as they age – like their food intake, potential cat illness, and activity levels.

How old is my cat in human years?

It’s important to note that there’s no reliable scientific way to calculate the relationship between human and cat years and this is more just to give us a sense of relatability, but this is a good rough outline to guide us.

How many cat years are in a human year?

The first year of your cat’s life is considered the equivalent of 15 human years. The second year adds nine more human years, so 2 cat years are approximately 24 human years. After this, each additional human year is four ‘cat years’ i.e., age 3 will be 28 human years or if your cat is six years old, it is equivalent of a 41 year old human.

Cat age chart

See the differences between cat years and human years with our cat age chart below.

Find out how old your feline friend is using our cat age calculator

Check our calculator at the bottom of the page and find out your cat’s age in human years at a glance.

What is the average cat’s life expectancy?

The true answer is that it depends, but indoor cats usually live longer than outdoor cats. The average indoor cat lifespan is 16 to 18 years and some even reach (or pass) the venerable age of 20. Most outdoor cats have an average lifespan of 13-14 years although life in the great outdoors brings its share of hazards that can shorten that lifespan.

Life expectancy in cats also varies depending on the breed, as some cat breeds will naturally live longer than others. For example, Siamese and Manx breeds are said to live the longest, so they could reach a ripe age in human years!

Did you know? According to some sources, the world’s oldest cat lived to be 34? That’s 153 in human years! Read more fascinating cat facts here.

Thanks to improvements in veterinary science and living safer lives, cats’ life expectancies have increased dramatically in the last few decades. Although it’s never enough, we’re getting to spending more and more time with our feline friends, and that can only be a great thing.

How do cats age in human years?

Cats age very quickly in their first two years of life, after which the process slows down and becomes more gradual. The way in which a cat’s age is determined is based off its physical and behavioural changes. These stages are then matched to those of a human life cycle. 

Why is it important to know a cat’s age in human years?

It is important to understand the life stage that they are at so that you can prepare yourself for any age-related health issues that may occur. Comparing this to human years helps us to do that better. Knowing when your cat has transitioned into their mature, senior cat years will help you give them the best care possible. 

How can I tell my cat’s age?

If you haven’t had your cat since they were a kitten, you might not know how old they are. The best way to find out is to take them to a vet who will be able to give you a good estimate. They will look for tell-tale signs to help ascertain a cat’s age and health. 

You (or your vet) can look for these signs in their teeth, fur, eyes, muscles and bones. We have more information on this below.

Teeth

Teeth can’t pinpoint the exact date for your feline friend’s birthday party, but they are still a great indicator of a cat’s age. The milestones are:

• A kitten’s first teeth appear between two to four weeks.
• Their permanent white teeth come in at around four months.
• Yellow stains (aka tartar) on a few teeth can mean your cat might be between one or two years old.
• If the stains appear on all teeth, the cat is likely at least three to five years old.
• Missing teeth are usually a sign that your cat is a respectable senior, between 10 to 15 years of age.
• But keep in mind that some cats can just have worse teeth than others regardless of their age. This could be due to breed, upbringing, diet or health.

After 12 years of age, cat’s eyes usually start showing cloudiness. And if you notice regular tearing and eye discharge, you probably have a senior cat on your hands. Do mention this to your vet though as there could be other causes rather than purely age.

Muscles and bones

Age can hide behind appearances so pay attention to features that can complete your cat's age picture. As in humans, a higher activity level gives your cat muscle definition. Playing, jumping and running are a young cat's game. So, if you notice that your cat tends to lose muscle mass or they don't like to move around too much, this might be a sign of ageing.

Older cats may be bonier, have extra skin hanging or protruding shoulder blades. Read our cat body condition guide for more tips.

Coat

A cat’s fur changes with age. Fine, soft fur is usually reserved for young cats. Older cats  often have a thicker, coarser fur, sometimes with patches of grey hair.

Now you know all about cat lifespans and how their age converts in human years! Keep reading on our content hubs for more advice about cats, including kittens and senior cats.

Find out how old your feline companion is in human years using the age calculator below: