How Long Does A Kitten Stay A Kitten?

kittens sleeping in a basket

There’s no doubt about it, kittens are adorable! But have you ever wondered how long they stay kittens?

Although cats are not considered adults until they are a year old, they aren’t really kittens either for most of that first year. They grow rapidly, and the true kittenish phase only lasts until they are 10-12 weeks old. After that, they are considered juveniles and begin to look more like adult cats.

That doesn’t mean they stop acting like kittens though. Cats usually continue to act very kittenish well into their first year of life and even beyond.

Let’s look at the kitten’s growth phases and see how long they remain “true” kittens.

Kittens are Born Tiny and Cute

A newborn kitten will fit easily in your hand. These tiny creatures weigh a mere 3-5 ounces at birth. When they first come into the world, kittens are almost entirely helpless; they depend on their mother for warmth and food.

However, these tiny bundles of fur will rapidly transform into full-grown cats. If you’ve never had a newborn kitten in your life before, you will be amazed at how quickly they grow and develop.

Let’s have a look a the kitten’s developmental milestones to see if we can figure out when they are “no longer a kitten”.

Growth And Development Through The Kitten Stage

Kittens will go through various stages of growth before reaching adulthood. During this time, their body size and weight will increase dramatically, their physical features will become more pronounced, and they’ll grow to be more independent.

tiny grey and white kitten whose eyes are barely open

The First Three Weeks

Newborn kittens are born with closed eyes and ears and are unable to see or hear for the first week or so of their lives. By the end of the first week, they will have doubled their birth weight but are still capable of little more than eating, sleeping, and cuddling.

Their eyes start to open during the second week, but their vision is not well-developed yet. During the third week the kittens’ eyes, which are initially blue, may begin to change color. This is also the time when their ears open up and they start to hear sounds.

By the end of the first three weeks of life, kittens can see and hear, and are starting to take their first shaky steps. Their weight at this point has tripled or even quadrupled from what it was at birth. Large breed kittens, such as Maine Coons, may even weigh as much as a pound (16 ounces) by now!

They are also starting to get their teeth now, and will soon be ready to start eating solid food.

Weeks Three Through Six

During the fourth week, as the kittens’ balance improves, they become more confident in walking and are eager to explore their surroundings.

As they are now able to balance themselves well enough to use the bathroom without any assistance from their mother, they are ready to be introduced to the litter box.

To teach kittens how to use the litter box, simply show them how it’s done by letting them observe their mother and nature will take it from there.

The kittens will begin to develop more independence from their mothers. They become more active and start to explore the world around them by playing with toys, chasing each other, and investigating corners of their home they may not have seen before.

They are able to eat solid food starting in week five. They are not yet able to chew hard kibble but are usually quite happy to start nibbling on soft canned food. However, they will continue to nurse for a few more weeks before they are weaned.

grey tabby kitten looking curiously at the camera as if asking "how long does a kitten stay a kitten", isolated on a white background

Weeks Seven Through Nine

By the seventh week, the kittens are now moving around with dexterity and confidence. Their true eye color will have become apparent. They are eating more solid food and will be weaned entirely off their mother’s milk by the end of this phase.

Many people think that once kittens are weaned they are able to go to their new homes. However, this is not usually the case. At this point, kittens are still very dependent on their mother for socialization and learning.

We now know that kittens continue to learn proper cat behavior from their mothers up until at least 12 weeks. So it is important that they not be taken away from their mom and siblings before they are 10 weeks old, at the earliest.

At eight or nine weeks old, kittens should get their first vaccinations. They will need two more vaccinations after this, at 12 and 16 weeks. This is critical for protecting them against potentially fatal diseases.

Weeks Ten To Twelve

At 10 to 12 weeks old, kittens can finally be adopted and taken away from their mother. Although they are not yet adults, they are no longer considered infants.

By the time they reach 12 weeks of age, they are starting to resemble the adult cat they will come more than they do a kitten. This doesn’t mean that their kittenish ways have disappeared though. They still need plenty of play and cuddles from their people.

Most people who get kittens are bringing them home between 8 – 10 months of age. There is a lot to consider when getting a new kitten, and a lot to do to prepare for bringing them home.

If you are thinking about getting a new kitten, make sure to check out our New Kitten Checklist for everything you need to know.

grey and white long haired kitten

Finishing Growing Up – 3 to 12 Months

At three months, young cats still have a lot of growing up to do, and it happens fast!

They reach sexual maturity at around six months of age, on average, though some reach puberty as early as four months. Cats should be spayed or neutered when they are six months old, to make sure to avoid unwanted pregnancies.

Because they are still growing, cats should be fed kitten food until they are 12 months old. After that, they can be switched over to an adult-specific diet.

By one year of age, cats are considered adults, though they won’t reach their full size until between 18 – 24 weeks of age. Some large breed cats do not reach their full size until they are three.

So How Long Does A Kitten Stay A Kitten?

As I write this, my Bengal kitten is sleeping on the desk beside me. I look at her and realize – she is not a kitten anymore! She just turned five months old and, in almost every way, she is no longer a kitten but a cat.

Unless you have a female cat that has kittens, you will likely never get to experience a true “kitten” – the clumsy, bumbling, endearingly charming balls of fluff that are kittens just a few weeks old.

Cats grow so fast, the true kitten phase goes by so quickly. If you bring home a kitten at eight weeks old, you will have just a few short weeks before it morphs into a small version of the adult it will become.

how long does a kitten stay a kitten? Tiny brown and white tabby kitten cupped in a woman's hands


Although cats are not considered adults until they are a year old, they aren’t really kittens either once they reach three months of age. The true kitten stage only lasts to about ten weeks of age, and it goes by in the blink of an eye.

If you are lucky enough to experience a kitten in your lifetime, be sure to savor every moment – they don’t stay little for very long!


  • Dr. Wendy Wilkins, DVM, PhD

    Dr. Wendy Wilkins is an experienced veterinarian and epidemiologist with over 20 years of expertise. She holds a Doctor of Veterinary Medicine (DVM) degree and a Doctorate in Epidemiology from the University of Saskatchewan. Throughout her career, Dr. Wilkins has excelled in clinical practice, academia, research, and regulatory veterinary medicine. She is a respected voice in knowledge dissemination, delivering factual information in a readable and understandable manner through articles, books, and public engagements.

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