When Do Cats Stop Growing? From Kitten To Adult Feline



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Cats change significantly in their physical appearance, maturity, and temperament during their growth process. And as a cat owner, it helps to know about all the changes your cat goes through.

Cats go through different stages of growth, from when they are kittens to when they become adult felines. Knowing about cats’ different developmental stages is essential to understand their needs during each phase better.

When Do Cats Stop Growing - from kitten to adult feline. Pickles, the black British short-hair cat lying stretched out on his side in the grass.

New cat parents often ask how long it takes for kittens to become adult cats and how big they are. This article will answer questions like when cats stop growing and become adults.

Let’s begin!

At What Age Do Cats Stop Growing?

Although experts argue about the exact specifics of when these stages begin and end, every cat goes through six fundamental stages of growth until it is fully developed.

These stages are:

Neonatal Stage

The neonatal period begins right after birth and lasts for about nine days. At this time, the newborn kittens keep their eyes closed. They can sense things only through touch and smell, while their other senses remain inactive.

They have limited mobility, so they cannot carry out basic life functions themselves and depend entirely on their mother for survival.

Transition Stage

After the first nine days of dependency, kittens transition until fifteen days after birth, when their other senses become functional. Kittens open their eyes and ear canals at this stage.

They also gain mobility and start acting of their own volition. Kittens will also be able to consume solid foods in addition to breast milk.

Socialization Stage

Two weeks after birth, kittens start to become more playful and agile. You often see them running around and socializing with their siblings through chasing or other hijinks.

Cats are affectionate animals by nature, and the socializing stage is vital in enabling this personality trait. If a cat does not interact much with others, it will become timid or aggressive, making it difficult for them to adjust to a new home.

Exposure to other animals and people in a safe environment helps kittens adapt to new surroundings faster. They learn to interact and become at ease in social situations. This makes the kitten more friendly and trusting.

Cats are most amenable until they are 7 or 8 weeks old, which is the duration of the socialization period. Older cats can also socialize, but trusting others will take longer.

Why Do Cats Knead? This article helps to explain some of your feline friend’s behavior.


After eight weeks of life, kittens enter the stage of adolescence and officially become young adults. They become relatively relaxed, but they remain incredibly active.

During adolescence, a kitten starts to form its definitive shape and size, but the time to reach full size depends on its breed and genetic factors.

After 3-4 months of age, a cat’s baby teeth fall out, making space for the adult teeth.


Puberty in cats is quite similar to that in humans. A male cat reaches puberty at seven months, while it takes females between five and eight months to reach sexual maturity. You will see rebellious and disobedient behavior from cats during this period, and their temperament will fluctuate. And as puberty nears its end, cats become more docile and mature. Cats should be neutered or spayed around 5 months old.


A cat physically becomes an adult, meaning it stops growing upon reaching the age of one year, although this period can differ with different breeds.

Most cats stop growing between ages 12 and 18 months, but their social and behavioral traits continue to change until they are 2 or 3 years old. It is then that cats become calmer compared to young kittens and reach emotional maturity.

How Big Do Cats Get?

Larger breeds like Maine Coon cats can take up to four years to reach full size and can come to weigh around 20 pounds. A British Shorthair needs three years to complete developing physically and reach adulthood.

Smaller cat breeds reach adulthood early, so Persian and Siamese cats stop growing after one year, while European cats need two. Bengal cats reach full size in 1-2 years, Ragdolls in 4 years, and Savannahs in 2-3 years.

The size of an adult cat also depends on its genetics. Felines with pituitary gland diseases will see stunted growth and often have incomplete maturation. This condition is also called pituitary dwarfism and is often the result of a genetic mutation.

Dwarf and munchkin cats are examples of such genetic mutations, which is why they are oddly small in size.

Gender also plays an essential role in a cat’s growth. Male cats stop growing later than female cats and tend to be larger because they grow slower.

Reasons Why Your Cat Is Not Growing

Cats almost double in size during the first six months of life, but some people report that their cats are not growing or gaining weight as they should.

It could be due to the following reasons:

  1. Your cat belongs to a smaller breed.
  2. If your cat is not regularly dewormed, it may become infested with parasites, stunting its development.
  3. Poor nutrition can also hamper the growth of a kitten. Adult cat and kitten food have different nutritional values, so you should give your feline friends age-appropriate food.
  4. Your cat may stop growing if it suffers from congenital hypothyroidism, pituitary dwarfism, portosystemic shunt, or mucopolysaccharidosis.

If your cat is not growing correctly, you must immediately take it to a vet.

Final Thoughts on Cats Growth

Many factors affect a cat’s growth, such as proper diet and environment, but, in general, cats stop growing after 6–12 months, except for larger breeds.

Cats may continue to get bigger after this period, but it is likely due to weight gain rather than an increase in bone size.

You must consult your veterinarian on your cat’s nutritional needs during the different stages of its life to allow it to grow at a standard rate.

Before you go, you might find these articles helpful:

Is It Okay For Two Cats To Share A Food Bowl?

Can You Use Baby Wipes On Cats?

Ways To Lengthen Your Cat’s Lifespan

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