When a youngster reaches the age of 18, society typically treats them as an adult. Yet, what about the feline members of our family? How old do cats become mature adults? Exactly when do you switch them over to adult cat food? At what age do cats stop growing?
There is no set answer to at what age do cats stop growing, and maturing; however, she will reach numerous milestones that indicate she is becoming an adult cat.
There is no set age at which a cat stops growing and becomes mature, although there are ranges of ages at which this occurs with some degree of regularity. This is what to anticipate while your cat goes through the change.
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At What Age Do Cats Stop Growing
According to Dr. Nicole Fulcher, associate director of the Animal Medical Center of Mid-America, “kittens normally cease growing at roughly 12 months of age.” However, they may still have some filling out to complete. A kitten of 12 months is the human equivalent of a teenager. At 18 months, they reach maturity, the human equivalent of age 21.
Most cats reach their adult size by the time they are 12 months old, although this is not always the case. Your cat will likely reach its full adult size between 12 and 18 months; however, any further growth at this time will be significantly slower. Some felines, however, may take up to two years to mature into adulthood. Particularly with larger breeds, this may take more time. For instance, Maine Coons may not mature into their maximum size until they are about 2 years old.

Common cat breeds, and when they stop growing
Generally speaking, the average lifespan of a tabby, siamese, or domestic shorthair cat is 12–19 months. Adults typically weigh 10–22 ounces and measure 13–16 inches in length.
- After the age of four, most Ragdolls have finished developing. A fully grown specimen would typically measure between 15 and 26 inches in length, stand 9 to 11 inches tall, and weigh between 8 and 20 pounds.
- Once a Savannah cat reaches age two, its body size stabilizes. Adults often measure 20–25 inches in length, 10–19 inches in height, and 12–20 pounds.
- The average lifespan of a Maine Coon cat is four years. Adults typically weigh 25 pounds and measure 48 inches in length.
- The maximum age for a Bengal cat is two years. A fully grown specimen would often measure 13 to 16 inches in length, stand 11 to 13 inches tall, and weigh 10 to 22 pounds.

The life cycle of cats: from kittens to seniors
We should review the fundamental phases of a cat’s existence before delving into the specifics of when, how, and at what age do kittens stop growing. Although the specific dates may vary from cat to cat, there are generally five distinct phases to a cat’s existence.
Kitten (up to six months old):
In kittenhood, a cat’s development is at its peak in terms of growth and change. This is also a formative time for them.
Junior (6 months old to 2 years old):
Cats maintain their rate of development and maturity. Keeping up the playful interaction with your cat can help it feel secure and certain during this time.
Prime Adult (3-6 years old):
The adult years are a time of peace and prosperity for cats; they have found their place in life and are often at the peak of their health.
Mature Adult (7-10 years old):
The aging process in cats is quite similar to that in people; they grow less energetic and more prone to weight gain and health problems, including renal disease and diabetes.
Senior (11-14 years old):
The average lifetime of a cat is 10-15 years; however, as they age, their health usually starts to decline.
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When Do Adult Cats often Stop Growing?
By the time they’re a year old, most experts say, cats’ personalities have fully developed and settled into patterns they’ll maintain throughout their lives. The growth rate of a cat, however, varies greatly. The average lifespan of a cat is between 18 months and 4 years. The first week after a kitten is born is crucial for its development.
Kittens often double in size during the first week of life. A kitten’s first week is the most critical since they gain roughly an ounce every three days after that. Since they only weigh around 3.5 ounces at birth, their growth rate throughout the first year is far higher than at any other time. Kittens will start to stand and toddle about during the third or fourth week. By the time they are 16 weeks old, kittens have finished their rapid growth and formed their most lasting impressions. Different cat breeds mature at different rates.
The growth rate of a cat may also be affected by its breed. Of course, the greater distance to maturity means that bigger breeds take longer to finish developing. The biggest breed of domestic cat, the Maine coon, takes up to four years to achieve its peak size.
Factors that determine the size of your kitty
Sex:
Male cats mature more slowly and are bigger than average compared to female cats. The average boy may expect to reach adulthood up to two pounds heavier than his female sibling.
Fixed or Intact:
Contrary to common opinion, spaying or neutering your cat usually won’t influence their development. Kittens should be altered by a veterinarian between the ages of 6 and 12 months, but in shelters and rescues, it’s generally done sooner to prevent unwanted pregnancies.
It’s crucial to remember that a kitten’s risk of developing capital physeal fracture increases if the animal is sterilized at an unsuitably early age. This condition is more common in male cats, especially those overweight. Because of this, you should always talk to your vet and, if necessary, acquire a second opinion.
Birth order:
The runt of the litter may continue to be the smallest member of the group, even as an adult. For kittens whose mothers were on the diminutive side, the lower down the birth line they fell, the smaller they were likely to grow up to be.
The number of siblings:
The significance of the litter size cannot be overstated. The milk supply may be exhausted if a mother cat has too many kittens. If kittens aren’t properly fed, they may develop slowly and shrink in size.
Diet:
If you feed your body well, it will develop healthily. For the first year of its life, you should feed your kitten a balanced, nutritious diet of kitten food. While bigger cats still developing may need kitten food for longer, most healthy cats of about 10 pounds in size may switch to adult cat food when they are a year old. Your veterinarian may recommend the finest food for your cat and provide you with advice on how much to feed your kitten.
Genetics:
There are a few reasons your cat can be on the tiny side, some of which are inherited. Bone abnormalities and short stature are among them. At the time of a regular exam, your vet should be able to notice any anomalies.
How To Recognize When a Cat Has Matured To Its Maximum Size?
Cats may keep growing even after their first year, although their pace of development will considerably slow down. Unless you keep a close eye on them, you may not even realize they’re expanding! You can tell whether your cat is still growing by measuring and weighing it every month. The average cat grows in length and height (from the floor to the top of its shoulder). Once a month, take your cat’s measurements to see if there is any change.
AT WHAT AGE DO DOGS STOP GROWING?
The heaviness of a cat provides information about its maturity and age. A cat’s mature weight may be estimated by taking its weight at 16 weeks of age and doubling it. The number you just guessed is probably quite close to your adult cat’s weight. Although it is not an exact answer to at what age do cats stop growing. If you want to know when your cat achieves full size, it’s a good idea to weigh him or her every month. Your cat will always want a mountain of devotion and cuddles from you, no matter its size.