When Do Cats Stop Growing?

Pet Health


March 12, 2021

Kittens are incredibly playful creatures that are going to mature and grow up very quickly. In fact, you might be surprised at just how quickly your little kitten turns into an adult cat, and its ways begin to change. However, when do cats stop growing? What is the ideal timeframe for a kitten to reach its maximum size and mature mentally?

The answer, as you might think, is not straightforward. First of all, you should know that it varies primarily based on the breed of the animal. Usually though, kittens tend to mature when they reach one year of age. Most cats reach adulthood by the time they are 12 months old, though you should know that their size will continue to grow up to four years of age.

The Cycle of Cats: Kittens

Understanding the entire cycle of cats as they turn from kittens into adult cats is important. Before we talk about their growth, you need to understand that the animal grows much quicker than others, and the exact dates are obviously going to vary depending on the breed, but you should know that the standard life cycle of the animal can be broken down into five major stages.


This period lasts from the time the animal is born until it reaches six months of age. This is also the time when the cat grows the fastest and develops really quickly. More importantly, the first six months are the most impressionable for the animal. It’s also the time when your kitten is going to be most playful and you are going to have a lot of fun with it.


This period lasts from six months until the cat reaches two years old. You will notice a stark decline in the cat’s energy levels and their growth and maturity will continue. It’s imperative that you continue to play with your cat during this period as well, because the cat needs to feel comfortable and confident in its surroundings. If it doesn’t, you are doing it wrong.

Prime Adult

By this stage, the cat has settled in well into its life, and is deep-set in its ways. When the cat is a prime adult, you will find it sleeping for most parts of the day. Prime adult cats are generally relaxed and very friendly among their owners.

Mature Adult

This is the period between 7 and 10 years of age, where the cat has grown and become a mature adult. By this time, the cat will become much less active, and they are likely to gain quite a bit of weight over time as well. As the activity levels of the animal decrease, they are likely to develop other problems, such as diabetes or kidney issues.


This is the period between 11 and 14 years of age, and it turns into a senior cat by this stage. The health of the animal is likely to deteriorate by this point in time, and you will find yourself taking the cat to a vet more often than you would like. This is the time when the animal will begin to laze and sleep around for large parts of the day, and the only thing you have to do is be there for the animal.

When Does the Cat Reach Its Full Size?

Most experts will agree that a cat will reach adulthood by the time it hits 12 months of age. Essentially, this is the age when the animal will mature and will now solidify into its ways. This is how the animal is also going to behave throughout its adult life.

So, if you paint a strong impression on the animal and give it proper care, it’s going to be well-set in its ways and will develop a firm routine. When the kitten is born, it usually doubles in size by the first week. Kittens grow very quickly and tend to grow by an ounce in a day after their first week. Kittens are born weighing around 3.5 ounces, so their growth rate in the early stages usually outpaces all other growth phases.

Furthermore, you should know that there are some cat breeds that tend to grow faster than others. For instance, consider the example of the Maine Coon, the largest domestic breed of cats in the world. The Maine Coon can take around four years to reach its full size, which is much longer than any other cat.

Various Factors Affect Cat Growth

This might come as a surprise to you, but you should know that there are plenty of different factors that affect the growth of the animal. Breed isn’t the only determinant when it comes to feline growth. For starters, you should know that kittens need to consume a considerable amount of calories on a daily basis, especially during the first stages of their life.

If the cat doesn’t get enough food, its growth is going to stop. That is one of the main reasons why so many kittens that you find in shelters are generally stunted or unable to reach their full size; they simply don’t get enough food. Apart from important variables such as breed and the cat’s diet, you should know that the time at which the cat is neutered or spayed also has an impact on the animal’s growth.

According to a particular study, a cat that was neutered or spayed earlier in its life will also affect its growth rate. Cats that are spayed and neutered are likely to grow larger over time. Furthermore, you always need to keep in mind that deformities and dwarfism may restrict the cat’s growth.

How Do You Know When Your Cat Has Reached Its Full Size?

While it’s apparent that your cat will continue to grow after its first year, you should know that their growth rate is going to dip sharply. If you aren’t paying close attention, you might find it difficult to figure out any difference. The best way to keep a check on your cat’s growth is to weigh it and measure its height and length once a month.

Remember, the cat’s height is going to grow over time, and if you weigh your cat and measure it at least once a month, you will get a firm idea when the cat stops growing. You should know that the weight of the animal will also give you a clear idea about the animal’s maturity levels.

For instance, you can estimate the cat’s average adult weight by weighing it when the cat is around 16 weeks old, and then doubling that figure. You will get a rough idea about the cat’s weight. Remember, you need to make sure that you give your cat lots of love and affection, no matter how old it gets.

It’s important that you spend time and pay attention to your cat because they are generally sociable animals and will want to spend time with you as much as possible.