When Do Cats Stop Growing? How Long They Stay a Kitten?

Written by

Amy Sawy

Veterinarian. DVM


Joseph M. Plummer

Veterinarian, DVM, MVZ

when do cats stop growing

Kittens are adorable creatures that come in the smallest of sizes! When you first get them, they’re stumbling around mewling for milk, and soon enough, they’ll be adults. So, let’s tackle the question of when do cats stop growing?

When a cat reaches 12 to 18 months, they’re considered an adult cat! At one year old, they’ve only started the beginning of their maturity, and it’s only a few months after they’ve achieved total growth.

Cats Growth Process

Cats reach full size quickly because of their fast growth rate and can show physical differences in just a few weeks. Sooner or later, the tiny kitten you had at the beginning would be a chunky adult cat perfect for warming up your lap!

Young kittens will be hyperactive and can be three times more active than cats fully grown.

Still, as soon as they reach adulthood, they’ll quickly sleep more extended periods and tone down on their energy. It’s at this time when their love for sunshine nap times peak!

There are many specifics regarding the size and timeframe for when cats become full grown.

How Long Do Cats Grow?


Cats become fully grown when they at least reach 18 months of age, but they become adults at one year old.

At this age, their training and mannerisms are solidified for the rest of their lives. So, if you’re planning on raising a well-behaved cat, the crucial period for their training is before they reach adulthood!

Their growth rate greatly depends on their nutrition, so if you want to make your kitten grow faster, you must feed them the right food.

At what age do cats stop growing? The timeframe for cats can differ from 18 months to 4 years old, depending on the kitten’s parents, their mother’s treatment during pregnancy, and the environment they’re raised in.

The Size of Fully Grown Cats

Once cats reach the age when they stop growing, they can all be of varying sizes. Their size, weight, height, and length can differ depending on their breeds and parents.

If they’re given the right amount of care, they can reach the average size for their breed.

When kittens stop growing in adulthood, they can reach a size of 10 pounds, 10 inches tall, and 18 inches long on average for domestic cats.

Male cats stop growing along with female cats in the same timeframe, but the size difference can differ.

The major differences between female and male cats can be:

  • Male cats are generally larger than their female counterparts
  • A male cat’s paws can be more prominent
  • A male cat’s face is wider compared to the average female cat
  • Female cats are more petite and dainty
  • The size difference can be only a few inches, nothing more significant

In the average cat growth chart, a newborn kitten can start at 2 to 5 ounces, a small and fragile size, and end at 10 pounds after reaching maximum growth.

When kittens are still going through their growth stages, their body is still underdeveloped, so you must carefully handle them!

Take note of the quantity and the nutrients needed, and control your kitten’s intake for the best-growing progress!

Growth of Specific Cat Types


Not all cats grow the same, and genetics affect a cat’s growth besides the environment. Genetics is the type of cat breed they are descended from and their parents’ genes.

With all the breeds out there, the timeframe of their growth is still the average length, as discussed before. For this section, let’s discuss the growth of these specific cat types.

For domestic shorthair cats, we have:

  • Domestic shorthair cats stop growing at the size of 11-15 pounds for males and 6-12 pounds for females.
  • When we go onto their physical size, a domestic shorthair can go up to a height of 8-10 inches and a body length of 12-15 inches. This is the basic size of general cats.

With tabby cats:

  • Tabby cats stop growing at the same size since they’re also domestic shorthairs. After all, tabby refers to the pattern and not the breed.

With black cats:

  • As for when black cats stop growing, the same answer for tabby cats applies since we’re looking at the breed and not the color.

With Siamese cats:

  • Meanwhile, Siamese cats are pretty similar in size to American shorthairs but are a little larger.
  • Siamese cats stop growing when they reach around 11 inches tall and 13-16 inches long.
  • As for their weight, they can be pretty hefty, the same as their height, and can be as heavy as 7-12 pounds.

It’s always fun to see the growth process of your cats. Suppose you want to see the average growth process for your cat’s specific breed from real people. In that case, many others on Reddit can give you their experience.

How to Ensure a Cat’s Proper Growth


There are many factors in play when it comes to assuring your kitten’s healthy growth. To let cats reach full size with the optimum weight, height, and length, you must take care of all their needs when they’re still kittens.

Pay attention to these five essential missions when it comes to raising a kitten:

  • Take preventive measures against potential causes of infectious diseases
  • Let the kittens familiarize themselves with you through gentle interaction
  • Allow the kittens to socialize with other cats.
  • Always make sure the kittens are clean
  • Give the kittens the correct nutrition required

The kitten stage is also the perfect time to train your cat but do it carefully as they’re still growing.

Once you dutifully accomplish these five essential missions, cats attain an adult size with no issues!


All cats, depending on their breed and other growth factors, can grow in different sizes and take different time frames. Still, cats generally stop growing at least at around 18 months old. Your favorite kittens would have already reached adulthood in just a short time.

To this end, you now know the answer to the question ‘when do cats stop growing?’ If you know any other fur parents who recently got a kitten, share this article, so they will know how long it takes for them to reach total growth.

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