When Do Cats Stop Growing?

When I first brought my Maine Coon kitten home, he was a bundle of fluff barely bigger than my hand. Within a month, he had practically doubled in size. Now we’re a year on, and I struggle to fit comfortably on the same sofa as him when he’s fully stretched out.

They grow up so fast…

While Maine Coon’s are a little different from your average moggy, they share a common trait. Kittens grow into cats pretty darn quick.

The question is, when do cats stop growing and when are your little balls of fluff no longer kittens? When is little snowball going to reach her full size, and how do you know when you should be switching your kittens over to adult cat food?

By the time you’re done here, you’ll have the answers to all of those questions and more.

Let’s get started.

Cat Development: The Different Stages

Your kitten needs to proceed through various essential stages before they transform into an adult cat, just like a child moves through different stages to become a fully-grown person. 

There’s a bit of debate among zoologists (animal scientists) over exactly when different stages begin an end. However, there are a handful of fundamental states that all the experts agree on:

How Do I Know if My Cat is Still a Kitten?

Sometimes, when you adopt a cat, you’ll have a good idea of how old it is. Most shelters and breeders can give you this information. You might even be able to get a kind of birth certificate. However, if you’re taking in a stray, you won’t know for certain how old they really are. 

If you don’t know first-hand whether you’re caring for a cat or a kitten, knowing how to tell the two apart could give you some guidance when it comes to making decisions about what food they need, and what kind of vet visits may be on the horizon. 

Here are some pointers that could help you to figure out if your cat is still a kitten.

When do Cats Stop Growing: How Big Will Your Cat Get?

Usually, the biggest question that cat parents ask us is “when do cats stop growing in size,” or “how big will my cat get?” The average house cat is usually around 10 pounds in weight and about 46cm (18 inches) long without the tail. 

Another point to note? Mr. Kitty is likely to get a bit bigger than Mrs. Kitty. Male cats are generally a lot bigger than female ones, because the growth of a male lasts a little longer. Because of this, male cats may be up to 2 pounds heavier than their female counterparts.

When Do Cats Stop Growing: Considering Breed

Usually, the average cat will stop growing completely after about year 3 of their lives. You probably won’t notice a lot of growth after year one, unless your cat loves their treats, in which case you might see an expanding waistline.

However, while all domestic cat breeds stop growing quite fast, there are some variances between breeds. For instance, giant cat breeds like the Maine Coon can take up to four years before they reach their full size. Savannah cats and Domestic Shorthair cats are also relatively slow-growing too, often taking around 2-3 years to achieve their full size. Here are a few common breeds and when they stop growing in most cases:

Let’s look at some of the more popular breeds in greater depth.

We're looking at the average size range of a fully grown cat in these breed examples and giving a normal maximum size. With some breeds the sizing is pretty consistent, but with others the height and weight range of a fully grown cat can be very wide.

Bear that in mind when comparing your kitty to our chart or listings of the size of a fully grown cat and for when that breed of cat stops growing.

We all know there's some massive Maine Coons and Savannah cats out there, but there's also a few oversize domestic moggies too!

When do Kittens Stop Growing?

One thing to keep in mind here is that although your cat’s weight will depend on their breed, you’ll need to keep a close eye on how much weight your four-legged friend is gaining for the sake of their health. The last thing you want is an overweight moggy. What’s more, felines that are underweight can often be more likely to suffer from various pathologies too!

With that said, you can expect a kitten to be growing at a pretty impressive rate. Whilst your kitten might look like an adult cat by the time they are 6 months old, most breeds are still growing to some degree up to a year old and then, as we've seen, in some cases for a while longer.

The average cat weight will help you see where in their growth your cat is so we've put together this average cat weight chart:

However, we’d recommend checking with your vet on how much weight your cat should be gaining at any given time and it is breed dependent.

Kittens usually double in size within the first week and grow an ounce every three days from thereon. For the first sixteen weeks of a kitten’s life, you’ll see the most growth at the most rapid rate. Make sure that you make the most of those playful kitten weeks while they last!

Is Your Cat Overweight?

If you’re a first time cat owner, it’s often difficult to tell whether your cat is growing correctly or gaining too much weight too fast. What’s more, if like me, you have a kitty that’s constantly begging for your food at every meal; it can be tempting to give them some extra treats. 

Unfortunately, overweight cats suffer from a number of health problems that can significantly impact their quality of living. To check your feline friend isn’t gaining weight too quickly, one option is to feel along your cat’s ribcage. For healthy cats, the padding shouldn’t feel too much thicker than the padding on your own hand. If you have to press quite firmly to feel your cat’s ribs, she might be piling on the pounds. 

Another way to check if your cat is gaining too much weight is to take a birds-eye view. Stand over your kitty and see whether her sides are bulging outwards. This could indicate that he or she is a bit on the tubby side. Remember, some cats are more likely to become overweight or obese. For instance, male cats are more likely to gain weight than females, and there are certain breeds that have a hard time preventing themselves from overeating.

Studies also show that free-feeding your cat by giving them a bowl of kibble to constantly graze on could mean that they’re more likely to end up overweight. 

If you think that your cat is a little chunky, don’t instantly switch to diet food. Your best option is to start by speaking to your vet. A vet will be able to tell you how much work you need to do to get your cat back to its ideal size. Many vets can also recommend certain kinds of food that ensure your kitty is getting the right amount of nutrients. 

Remember, when you are trying to reduce your cat’s weight, don’t jump into controlling her food intake and cutting back too quickly. Reducing the amount of food your cat has access to very quickly could lead to stress that presents other health problems for your feline. What’s more, switching immediately from a standard food to a diet meal could lead to sickness if your kitty isn’t used to the new ingredients. 

Most vets will recommend transitioning gently to a new diet with your moggy and making sure that he or she gets plenty of extra exercises. You can look for opportunities to spend more time playing with your cat, using toys that force them to run around more often. Alternatively, if you’re feeling comfortable and you’re willing to invest in some lead training, you could use a cat harness to take your cat out for a walk. 

What Other Factors Affect How Fast Cats Grow?

Remember, your kitty’s growth isn’t just affected by their breed; it’s also influenced by diet too. Kittens need to consume a huge amount of calories during the first stages of your life, so don’t worry if you think you’ve got greedy guts on your hands. 

Your vet can give you more insight on how much you should be feeding your cat based on your weight, and I’d recommend getting that advice. If cats don’t get the right amount of food, their growth could end up stunted. 

Another thing that changes how much your cat will grow is neutering. Studies indicate that cats that are spayed or neutered in early life could grow a lot larger than those not spayed until adulthood. 

That’s why a lot of vets will recommend waiting until your kitty reaches full sexual maturity before you spay or neuter. Keep in mind that things like dwarfism and bone deformities can also cause a cat’s growth rate to change too. 

The best way to know for certain when your cat has stopped growing is to measure and weigh your kitty each month. Cats can continue to gain height and length even after they reach the one year mark. If you measure your feline at least once a month, you’ll notice when the measurements stop changing, and you’ll have a chance to grab a quick snuggle in-between measurements.

When to Feed Your Kitten Adult Food

Probably one of the main reasons you’ll want to know when your cat is going to stop growing, is so you can decide whether to feed them kitten or cat food. 

Ultimately, the right time to transition to adult food is a bit subjective. Most vets recommend around 10-12 months is when you should make the move – but that’s variable. My young Maine Coon has a hard time with weight control (he burns food off fast). Because of that, my vet recommends keeping him on kitten food until he turns 2. On the other hand, if you have a kitten that’s gaining a lot of weight on kitten food, your vet might ask you to make the switch earlier.

Remember, kitten food usually has more calories than adult food to help your little fluff ball grow big and strong.

So, When do Cats Stop Growing Then?

The answer to the question “when will my cat stop growing?” isn’t as straightforward as most people think. In most cases, with a standard cat, you can expect your kitty to continue growing until they’re about 12-18 months old. 

However, if you have a more exotic cat breed, like  British Shorthair, or a Maine Coon, then you could easily have years of growth ahead of you. It’s also worth noting that many things can prevent a cat from growing to its full size, including bone deformities, and things like dwarfism. 

It’s not always possible to tell immediately how much your cat is going to grow. 

Kittens grow up fast – too fast, in my opinion. However, the good news is that if you raise them right, your kitties will stay adorable and playful for years after they stop growing. Some breeds even maintain their child-like mannerisms throughout their entire lives. 

No matter when your kitty stops growing, make sure that you’re using plenty of toys and activity to keep them physically and mentally engaged. Adult cats need to play just as much as youngsters. 

What’s more, remember that no matter when your cat stops growing, they’re always going to need hefty portions of love and snuggles. That’s something they never grow out of.

And, finally, read this if you find yourself asking "how long do cats live?", which is the other question we often hear from cat owners about their beloved kitty.

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