Small kitten being stroked.

Your Cat's Age in Human Years

4 min read

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.

How old is my cat in human years?

Although there’s no reliable scientific way to calculate the relationship between human and cat years, it’s generally agreed that the first two years of a cat’s life are roughly equal to the first 25 of a human’s. After this, each additional year is around four ‘cat years’. This means if your cat is six years old, their equivalent cat age in human years will be around 41.


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

Don’t worry, we’ve done all the math for you! 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 life expectancy of my cat?

The true answer is that it depends, but indoor cats usually live longer than outdoor cats. On average, indoor cats live 16 to 18 years and some even reach the venerable age of 20.

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 could reach a ripe age in human years!

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

Cats’ life expectancies have increased dramatically in the last few decades. Although it’s never enough, we’re spending more and more time together with our feline friends and that can only be a great thing.


How can I tell my cat’s age?

To find out how old your cat is, it’s best to take them to a vet. But you can still look for tell-tale signs of a cat’s age and health.


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.


If your cat’s teeth are not always the reliable indicator you hoped for, eyes can give you a useful clue regarding your cat’s age. The difference between a smooth iris and a crackly looking one can be the difference between a young cat and a senior one.

After 12 years of age, cat’s eyes usually start showing cloudiness. And if you notice tearing and eye discharge, you likely have a senior cat on your hands.

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 it doesn’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.


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

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:

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