How Long Do Cats Grow? (2023) | Working Out Your Cat’s Full Size

You’ve just gotten a kitten and it’s tiny, but is it possible this cat will outgrow itself? No matter the kind of cat breed, from Sphynx to Siamese, your feline friend is sure to grow as big as they possibly can.

Your cat hits similar developmental milestones to a human baby in its lifespan. However, unlike a human child, there is no definitive age where you’ll know for sure that your cat has stopped growing and maturing.

There are, however, estimated age ranges where most cats generally stop growing and reach full maturity. Unsure, how long do cats grow? When will you know your cat has stopped growing? This guide is filled with the answers to help you figure it out. 

Here’s what you can expect as your cat ages and develops.

Milestones for Growing Cats

You might not know what milestones are pivotal in a cat’s growth. So, here are some important mileposts to spot for kittens as they become adult cats:

Months 3-4: Baby teeth start to fall out and are replaced by adult teeth; this growth process usually ends by 6 months of age.

Months 4-9: Kittens go through sexual maturation. This is when the cat has come into season or ‘call’. Cycles of sexual activity typically occur every two to three weeks. They also become very vocal during this time.

Months 9-12: A kitten has almost achieved full growth.

1 year+: Kittens are entering adulthood.

2 years+: Kittens are socially and behaviorally mature.

After kittens are born, they usually double their size in their first week. After their first week, kittens grow an ounce approximately every three days. The average kitten weighs around 3.5 ounces at birth.

Kitten Growth Chart

Kittens typically grow eight times their size in just about eight weeks. Below is an estimation based on the average weight of kittens.

Under 1 week old: Kittens weigh less than 4 ounces.

7 to 10 days old: Kittens weigh 4 to 6 ounces.

10 to 14 days old: Kittens weigh 6 to 8 ounces.

14 to 21 days old: Kittens weigh 8 to 12 ounces.

4 to 5 weeks old: Kittens weigh 12 ounces to 1 pound.

6 to 7 weeks old: Kittens weigh 1 pound to 1 pound and 8 ounces.

8 weeks old: Kittens weigh 1 and a half to 2 pounds.

12 weeks old: Kittens weigh 3 pounds to 5 and a half pounds.

16 weeks old: Kittens weigh approximately 5 and a half pounds to 7 and a half pounds.

6 months to 1-year-old: Approximately 8 pounds to 15 pounds.

Feeding Habits Change as Your Kitten Grows

Some experts recommend free-feeding kittens once they are weaned and eating solid food so they can get as much food as they need. If free-feeding isn’t something you’d like to try, feed your kitten four times a day with a half cup of food at each meal.

Then, when they’re around six months old, you can adjust their feeding to around three times a day. After a year, reduce the amount to two meals a day.

Tip: Remember, always consult your veterinarian before making any sudden changes to their diet. Also, be sure to ask your vet how you can meet your cats’ daily nutritional needs.

When Should I Feed My Kitten Adult Cat Food?

The right time to transition your cat from kitten to adult food starts around 10-12 months of age.

However, if your little furball is struggling to keep weight on, it would be advisable to keep your furbaby on kitten food until they are 2 years old or even longer. On the other hand, a kitten who is maturing quickly and becoming overweight on kitten food could benefit from making the switch to adult food at around 8 months.

How Long do Cats Grow?

The average domestic feline weighs around10 pounds. The males of the largest domestic cat breed, the Maine Coon, weigh around 20 pounds. Despite the urban legend – there isn’t a correlation between your cat’s paw size and its height and weight.

Bigger paws don’t necessarily mean a bigger cat. The best way to determine how big your cat will grow is by its genetics. There are 19 pairs of chromosomes in cats that control everything from their hair length, coat color, and size.

When Exactly Do Cats Reach Their Full Size?

Most experts agree that cats reach adulthood at 12 months old, which generally means that this is the age where the cats’ personality has matured and solidified into how they’ll behave throughout their adult lives.

However, a cats’ growth cannot be calculated with the same consistency. In fact, cats reach full size anywhere between 18 months to 4 years of age.

It’s important to note, the best way to determine how long your cat will grow is knowing its background. Your cats’ parents are the best indicator of most of your cats’ personality and physical traits. Your cats’ ancestry is the key to learning more about your cat, from their features to their gut health.

Gender can also be a factor in their size. Males tend to be bigger than females, and the duration of their growth spurts can last longer.

Factors That Affect Your Cats Potential Growth

One main factor that may stunt the growth of a cat is a poor diet. From birth, cats need to consume a massive amount of daily calories during their first stages of life to reach their proper size.

If cats aren’t fed properly their growth can be stunted, which is why many previously homeless and abandoned shelter kittens are smaller in size and stature than their re-homed counterparts.

Some Cat Breeds Grow Faster than Others

Another factor that contributes to your cats’ growth (or lack thereof) is their breed. The breed of your cat can affect its rate of growth. Unsurprisingly, the larger cat breeds take longer to reach their full potential of growth due to longer time periods to reach maturity.

However, in addition to diet and breed, the age at which a cat is spayed or neutered also affects your furry friends’ growth rate. Research has shown, a cat that is spayed or neutered early in its life can have a slower or faster growth depending on the cats’ genetics.

Also, some diseases like dwarfism and bone deformities can cause an afflicted cat’s growth to be slowed or stunted.

When Do Cats Stop Growing?

Once your kitten has outgrown the “terrible twos”, many cat parents wonder if that means their cat has stopped growing.

The short answer is, no. This doesn’t necessarily mean cats over a year old will stop growing altogether. A cat who is mostly sedentary and has poor dietary habits can pack on fat. While a chubby, roly-poly cat is always cute, having an overweight cat is a very unhealthy condition for their general well-being.

Although the most common age for a cat to stop growing is around 12 months, not all cats reach their full growth potential at this age. Although, if they are still growing as they age it will be at a much slower rate.

There may be some cats that can take up to 2 years to achieve full growth. Large breeds, in particular, can take longer to reach this milestone. Maine Coons, for instance, might not reach their full size until they are approximately 2 years old.

Full-sized and Miniature-sized Outliers

Like most things in life, there is always an exception to any rule. These two examples below are an exception to the question, “how long do cats grow?”.

As mentioned earlier the Maine Coon cat breed can take up to two years to reach full size. The Maine Coon cat, named Stewie, held the Guinness Book of World Records record for the longest cat at 48.5 inches (123 cm) stretched out.

On the other side of the spectrum, cats with dwarfism can be abnormally small. Dwarf cats are the Lilliputians of the feline world. There are two different causes of dwarfism presented in cats: genetic mutation and a pituitary gland malfunction.

A miniature cat named Lilieput holds the Guinness Book of World Records record for the shortest cat. Lilieput measured at 5.25 inches (13.34 centimeters) from the bottom of the paws to the top of the shoulders

How to Tell When Your Cat Has Reached its Full Size

While it is true that cats can continue to grow after the first year, their growth rate will slow down significantly.

The best way to understand when your cat has stopped growing is to measure and weigh your cat once a month. Cats continue to gain height (determined from the ground to the top of their shoulders) as well as length. If you measure your kitty once a month, you’ll be able to note when those measurements stop changing.

A cat’s weight can also reveal its maturity level or approximate age. You can estimate your cat’s adult weight by weighing them at  16 weeks of age and doubling that number.

Be sure to note that this is merely an estimation and your cat’s weight may differ. Similar to measuring a cat’s height and weight, weighing a cat monthly can also aid in determining when he or she reaches its full size.

Final Thoughts on How Long do Cats Grow?

While kittens will stop growing at about one year old, it’s important to remember that most kittens will look like an adult around six months.

But of course, the main takeaway is to feed your cat a healthy diet. Always provide your cat with a fresh water source and enrich their environment with plenty of stimulating activities, such as places to climb (eg: a scratching post) and places to explore.

These cat caring practices will be sure to ensure your cat grows and matures efficiently. A strong and healthy cat is a happy cat, which is ultimately all we want for our furry bundles of joy.

Remember, no matter how big your cat gets, one thing is for sure, your cat will always need a record size portion of love, affection, and cuddles.

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