How To Tell A Cats Age When You Have No Idea How Old It Is

It is not uncommon to adopt a cat having no clue how old it is.

If you’ve got a cat and you don’t know how old it is then the best thing to do is to ask a vet. A vet will be able to give you an age that is more or less correct (within a couple of years or so).

The best factor for gauging a cat’s age is their iris, these change naturally with age, so a vet will carefully examine the iris to get a good idea of how old your cat is.

Your vet will also examine their teeth and coat as well as make observations about their sexual maturity. All of these factors combined will build a good (though not infallible) picture of what their age is.


Also Read: How To Work Out Your Cats Age In Human Years


If you want to have a go at aging your cat yourself then keep reading to find out what the tell-tale age indicators are:

1. Teeth:

Baby teeth, also called deciduous teeth, first emerge in kittens that are between 2 to 4 weeks old.

During this time, their permanent teeth are developing underneath the baby teeth, so that by the time the kitten is 3 to 4 months old, the permanent teeth will begin to replace the present baby teeth.

By 6 months old, a cat should have all their adult teeth.

keep your cats teeth healthy

In cats that are older than 6 months, the amount of staining, or tartar on a cat’s teeth can also be an indicator of a cat’s age, however a lack of tartar does not necessarily mean your cat is young it may just mean a previous owner has cleaned their teeth for them regularly.

Chips in the enamel or missing teeth are more common in older cats who have had more time to get into trouble and damage their teeth in falls or fights.


Also Read: How Long Do Cats Live?


2. Sexual Maturity:

Male kitten’s reach their sexual maturity between 6 to 12 months of age. However, this can sometimes occur as late as 18 months. A sign of puberty includes territorial spray or more prominent testicles. 

cat sanding withbottom towards camera

Female cats will experience their first estrus cycle, or first heat, sometime between the ages of 5 months and 12 months.

However, the length of sunlight that the cat is exposed to, along with the weight of the cat also has an effect of when the feline begins her first estrus cycle.

A female cat that is experiencing her cycle will show you signs visibly and vocally that she is on heat.

Along with this, a female cat can fall pregnant and give birth to her first litter by the time that she is 7 and a half months of age. 

3. Coat Development:

The hair or fur of a kitten is seen as soft and baby-fine. As the kitten grows, their coat will become thicker and coarsen. It may even change colour, becoming either darker or lighter in tone.

Cats can also develop grey or white patches in their fur as they become older. 

cat doin' a furniture scratch

An additional factor to this is how well a cat grooms itself, as this will indicate how old the cat is.

Older cats are often more relaxed in their approach to self-grooming weight gain, age, arthritis and dental problems can cause their enthusiasm for grooming to diminish.

Insuring an older cat:
Cats over the age of 10 can be very expensive to insure and it can be difficult to get lifelong cover for them.

Read our guide to senior cat insurance to make sure you don’t get ripped off.

4. Eyes:

Healthy kittens or cats that are younger than 10 years old have eyes that are very bright and clear.

They have no evidence of discharges. However, Cats that more senior in years often develop a cloudy appearance to their eyes.

However, if a cat is unhealthy, this can occur at a much younger age. Consequently, this examination is only accurate on cats that are in good overall health.

British Short hair cat with bright yellow eyes sitting on the sofa.

As cats age, it is normal for their iris to show some sort of change.

Iris Atrophy can occur which causes the breakdown of the inside of the iris so that the cat’s pupil does not get as small as they once did.

The inner edge of the iris can also become wavy.

Your cat’s iris is one of the best indicators of their age as iris change is a normal feature that comes with a cat aging which does not cause any pain or problems for the cat. 


Working out a cat’s age is by no means simple and it’s unlikely that you’ll be able to work it out with any degree of accuracy at home without knowing some of its history.

Take your cat to vet and they will be able to take all of the above factors into consideration as well as use equipment to listen to your cat’s organs and assess their health to give you a reasonably accurate picture of your cat’s actual age.


Ask a Vet

Speaking with a vet is the best way of getting a good idea of how old your cat is.

If you can get a few good pictures of your cat including their teeth and a close up of their eyes then the vets at JustAnswer could help.

JustAnswer allows you to talk in real-time to veterinary experts for a small fee.


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