Welcome To Our Complete Kitty Growth Guide! Answering Your Top Cat Size Questions, Such As When Do Cats Stop Growing? And Revealing The Differences Between Breeds.
Love can turn a wonderful blind eye to so many physical changes.
For instance, if you got your cat when she was a kitten, you can probably still recall what she looked like the very first time you met!
You may even still think of your full-grown cat as your palm-sized fluffy baby and continue to see her “inner kitten” long after her length, height and weight might say to others “adult cat!”
And truly, in some ways your cat will always be a tiny kitten to you.
But how do you know when your kitten is full grown?
What height, length, weight should you expect to see and how long will it take for your cat to reach that milestone?
Because different feline breeds grow at different rates and some breeds are quite petite at maturity while others can be surprisingly robust in size, this, too, can make answering the question of “when does a kitten become a cat?” very interesting!
When are kittens fully grown?
So, when are kittens fully grown? When do cats stop growing and reach their final size?
Most cat breeders agree that kittens stop growing somewhere between 8 and 16 months, depending upon the breed.
But there isn’t really any hard and fast scientific evidence to prove this.
And it’s quite a range of information.
Fortunately, there are a few other ways of looking at the question.
If you ask a feline veterinarian ‘when do cats stop growing’, you may get an assessment of your kitten’s progress toward adult cat-hood based on what vets like to call cat “life stages.”
However, these life stages are not based on your cat’s length, height or weight.
Rather, they are based on when your kitten is likely to reach other important life milestones.
Milestones include such things as being fully weaned and eating independently, becoming able to make kittens, achieving full range of vision and hearing.
They also include developing a full set of adult cat teeth, acquiring important social and predatory skills.
Completing the cycle of kitten vaccinations and similar other benchmarks.
Cat Life Stages
Here are the generally accepted life stages veterinarians use to assess kitten maturity:
Birth to 6 months: Kitten life stage.
7 to 24 months: Junior life stage.
3 to 6 years: Prime life stage.
7 to 10 years: Mature life stage.
11 to 14 years: Senior life stage.
15+ years: Geriatric life stage.
So here, you can see that you have plenty of important markers to watch for as your kitten grows up.
But you still don’t have any real concrete idea of when he will reach his full adult height, length and weight!
How fast do kittens grow?
The question of “how fast do kittens grow?” is one that must be answered on a breed-specific basis.
In other words, if you have a Bengal kitten, the answer to this question will likely be different than if you have an American Shorthair kitten or a Maine Coon kitten.
And if you have a “mutt” kitten – a kitten whose parentage is unknown or only partially known – figuring out when is a kitten full grown becomes even more of a mystery!
There are three possible ways to determine where your kitten is now compared to her breed’s kitten growth chart:
Height. Her full height from paw to shoulder.
Length. Her full length from nose to tail (start or end of tail depending on who is doing the measuring; sometimes the tail length is measured separately).
Weight. Her full weight along a spectrum at maturity.
Of these three, regardless of whether your kitten is purebred or a mixed breed cat, weight is the least reliable and should only be used as a backup source of information.
Why is this, you might wonder?
The reason is because veterinarians report they are seeing more and more cases of obesity in felines.
If your kitten came to you already overweight, or if he has been consuming more calories than he expends daily in energy, his weight might suggest he is closer to reaching his adult cat size than he actually is based on the cat life stages chart!
If you know (or think you know) your kitten’s breed, you can use this helpful guide from The Association for Pet Obesity Prevention (APOP) to monitor his weight.
It is also a great idea to talk with your veterinarian about your kitten’s weight, especially if you are not sure about his parentage.
Weight at each stage of life can be influenced by several factors. These include gender, reproductive status (fixed or intact), birth order, number of siblings, nursing status (birth mother or human foster parent), health of the parents and overall health.
Here, if your kitten was reared through nursing with her mom, she may reach her adult size more rapidly.
She may also have a better chance of reaching the larger end of the growth spectrum than if she was cared for by foster human parents with kitten formula.
And this is something you may or may not know, depending on how you acquired your kitten (adoption, breeder).
Once you and your veterinarian have determined an ideal weight range for your growing kitten, you can continue to monitor his weight for overall health reasons even as he continues to grow into his full adult cat length and height.
Kitten growth chart
As a new kitten parent, you will want to monitor your kitten’s overall growth (length, height, weight) from two perspectives: healthy kitten growth expectations and breed-specific adult cat growth expectations.
The former is critical to detect any situation where your kitten may fail to thrive so you can seek veterinary care without delay.
The latter is important to know both for health reasons and so you are not surprised when your (you thought) fully grown cat just keeps growing and growing!
If you want to find the answer to the question when do cats stop growing with reference to your own kitty, you can find out exactly this way too.
When your kitten is born, she may only weight a few ounces and will likely fit easily into your palm.
But every day from then on, she will gain between 0.25 and 0.5 ounces (7 to 14 grams), doubling her birth weight and size between day 10 and day 14.
From here, it is quite normal to see your kitten gain one pound during each of the first 12 months of life. Although smaller breeds may slow down on weight gain after reaching 6 to 8 months old.
As you track your individual kitten’s growth, it is also vital to write down her starting weight/height/length.
This is because breed, gender and other factors can influence whether she is at the low or high end of the growth spectrum.
Kitten Growth Markers
There are some ways we can assess how well a kitten is progressing.
Here are a few additional benchmarks to watch for:
3 month old kitten size.
By the age of 3 months (12 weeks), your kitten should weigh between 2 and 4 pounds and should be three to four times the size she was at birth.
4 month old kitten size.
By the age of 4 months (16 weeks), your kitten should weigh between 4 and 5 pounds.
If you plan to fix (neuter/spay) your kitten, vets often like to wait until the scale reads at least 4 pounds before scheduling this surgery.
5 month old kitten size.
By the age of 5 months (20 weeks), your kitten should weigh between 5 and 6 pounds.
6 month old kitten size.
By the age of 6 months (24 weeks), your kitten should weigh between 6 and 8 pounds.
For many cat breeds, reaching the 6-month milestone will also mean she is between half and three-quarters of the way to her full height and length.
Although she may continue to gain weight, length and height well past the 1-year mark.
However, for some breeds (read on to learn more about these), growth towards maturity happens much more slowly or more quickly!
For certain breeds, your cat may not stop growing until she reaches 18 months.
For still other breeds, how old are cats when they stop growing may take up to three or even five years!
Big cat growth chart
As we are taking a look at what age are cats full grown, the only way to get a true sense of how fast do cats grow is to actually take a look at different cat breeds and compare when are cats fully grown between different cat breeds.
First, we will examine five representative big cat breeds and investigate how long do cats grow in these breeds.
In fact, these five big cat breeds aren’t just big – they are huge!
Each of these cat breeds is considered to be among the largest domestic cat breeds in the world.
More importantly, as you will notice, the average age when do cats stop growing can vary greatly among these big cat breeds!
When do Maine coon cats stop growing?
Not only is the Maine coon cat the official cat breed for the state by the same name, but it is also officially the largest domestic cat in the world.
Speaking of which, guess which cat breed currently holds the world record for being the largest cat of any breed – ever?
If you guessed “Stewie the Maine coon cat,” who was measured at a whopping 48.5 inches long when he won the Guinness Book of World Records title, you would be right!
- Length: up to 48 inches
- Height: 8 to 16 inches
- Weight: up to 25 pounds
- Time to full adult size: 4 to 5 years!
When do Bengal cats stop growing?
The cat breed known as the Bengal cat has been described as a “small leopard,” and this isn’t so far from the truth, given that the original Bengal was a cross between an Asian Leopard cat and a domestic cat of unknown breed!
While Bengal cat size can range up to 22 pounds for some males, 16 pounds is more typical.
As with most cat breeds, a male Bengal cat full grown will be slightly heavier than females.
- Length: 13 to 16 inches
- Height: Up to 11 inches
- Weight: 10 to 22 pounds
- Time to full adult size: within 1 to 2 years
When do Savannah cats stop growing?
The gorgeous Savannah cat is actually considered a hybrid breed like the Bengal cat.
Half African serval cat (a wild cat breed) and half domestic cat, these cats have sometimes been described as looking like a “small cheetah.”
Determining how big do cats get in the Savannah breed depends on whether they are considered to be F1 through F6 class.
Only F1 represents a pairing of an African serval with a domestic cat, and will be larger than all other classes. F2 through F6 represents two Savannah cat parents.
- Length: 20 to 25 inches
- Height: 10 to 19 inches
- Weight: 12 to 20 pounds
- Time to full adult size: within 2 to 3 years.
When do Ragdoll cats stop growing?
The Ragdoll cat is a fascinating breed for a variety of reasons, not the least of which is that an estimated 45 percent of this cat’s DNA can be directly traced back to a single cat named Raggedy Ann Daddy Warbucks!
However, the Ragdoll cat actually gets its name from the tendency of these cats to let their bodies hang limply when you pick them up – kind of like you are cuddling a ragdoll!
- Length: 15 to 26 inches
- Height: 9 to 11 inches
- Weight: 8 to 20 pounds
- Time to full adult size: up to 4 years
When do British shorthair cats stop growing?
The British shorthair cat can actually trace its roots all the way back to ancient Egypt, which makes it one of the oldest known cat breeds of all time!
This cat matures quite slowly, but British shorthair cat enthusiasts say the final result is well worth the wait.
- Length: 16 to 22 inches
- Height: 14 to 20 inches
- Weight: 7 to 18 pounds
- Time to full adult size: 3 to 5 years!
When are cats full grown?
As you can see from the comparison of different cat breeds here, it can be very challenging to just look at your kitten and tell whether or not he is fully grown!
While as a general rule, bigger cat breed kittens can take longer to grow to their full mature height, length and size, this is not always the case.
But most importantly when it comes to answering the question of when do kittens stop growing, it is vital to remember that all cat breeds are sized along a continuum.
For instance, in the examples provided here earlier, the adult female cats will tend to stay closer to the low end of the length/height/weight continuum.
Conversely, the adult male cats will tend to hit or even exceed the high ranges of the length/height/weight continuum for the breed.
Most critical to remember, however, is that an individual kitten’s full adult size depends more on that kitten than on any other factor!
Determining at what age do cats stop growing can depend on a number of factors
When do cats stop growing?
You and your kitten have embarked on an adventure together!
This adventure is one of getting to know each other over a period of months and then years as you spend your lives together.
Watching your kitten grow up is a huge part of this wonderful adventure, as you marvel at how such a tiny little klutzy furry bundle can grow up into an amazingly powerful, intelligent, agile feline.
It is always a great idea to bring your new kitten for a veterinarian checkup as soon as possible – if possible, even the same day you bring her home.
This way, you can get a firm benchmark measurement for her health, weight, length, height and overall physical development right from day one.
From there, like many new kitten parents, you may want to keep a growth chart to monitor how her size changes from week to week.
Not only will this help you identify any possible health issues before they become serious, but it will help you really tune in to the small but significant changes she is going through every day.
You may never know the exact day your kitten becomes a cat in terms of her full adult size. But you can feel sure that together, you and your new kitten will enjoy every day of that journey together!
- Bukowski, J., DVM, MPH, PhD, et al, “Kitten Care,” Merck Veterinary Manual, 2016.
- Hoyumpa Vogt, A., DVM, DABVP, et al, “2010 AAFP/AAHA Feline Life Stage Guidelines,” American Animal Hospital Association, 2010.
- Bateson, P., “Behavioural Development in the Cat,” The Domestic Cat: The Biology of its Behaviour/Cambridge University Press, 2000.
- Zoran, D.L., DVM, PhD, DACVIM, “Feeding cats and feline obesity,” DVM360(CVC in Kansas City Proceedings), 2009.
- Remillard, R.L., et al, “Comparison of kittens fed queen’s milk with those fed milk replacers.,” American Journal of Veterinary Research, 1993.
- Pet Obesity Prevention.