When Do Cats Stop Growing? And How Big Will Your Adult Cat Get?

Kittens are like living, and purring tiny fur balls that take our stresses away. At times, their hyperactivity can be so much for us to handle, but we can’t simply say “no” to them, more so, be harsh for their proclivities as growing kittens.

Sometimes, we wish that they could stay the same forever, but we know they can’t. They have to thrive and be a fully grown cat. But when do cats stop growing?

When Do Cats Stop Growing? At What Age Cats Reach Their Full Size?

When do cats reach their adult size and finally stop growing? Each cat is unique but there are some general guidelines on how big your cat will get and how old he will reach that size.

So, cat parents should simply enjoy their kittens' cute stature, because it won't be long enough before they outgrow such a tiny figure.

Most cats based upon veterinarians are normally assessed with or near their full size by around the age of 11 months.

Some larger breeds may keep growing for some months after. Some of the largest cat breeds such as Maine Coons can reach their adult size as late as four to five years of age.

While a young kitten could have the physical characteristics of a mature cat, we must review the milestones that kittens progress from kittenhood to cathood!

The exact date of maturity varies slightly by breed but your little lively fluff ball may soon transform from being a kitten to a cat between ten months and 18 months.

For some, that might be long, but believe us when we say that you won’t even notice how time passes by each time you are with your little furball. Before you even notice, your kitten is already a cute and awkward teenager kitten.

And as your cat grows, his demeanor will also change. Sooner or later, you will have an intelligent and mellow cat, but still with occasional bursts of the playful spirit he once had as a kitten.

Nonetheless, one thing remains constant – each kitten brings joy and memories to their “hoomans” that will last a lifetime.

The Milestones for Growing Cats

Just like human babies, kittens also have developmental milestones that pet owners can anticipate with fervor.

As kittens grow, they experience the following general growth indicators, though the exact age to which any of the following happens can also vary a bit from one cat to another:

• 7 days: Kittens will open their eyes and their weight would double up to eight ounces.
• 21 days: Your growing cats continue to gain weight. They can weigh as much as 15 ounces. Most cats at this age can walk steadily, and their baby teeth are starting to show.
• 6 weeks: They can clean themselves, leap, and play with their siblings. They can weigh a little over one pound during this time.
• 8 weeks: Kittens are usually weaned at this age, and they can already be adopted.
• 3 to 4 months: A 3 to 4-month old kitten can already weigh between three to seven pounds, which makes them eligible for spay/neuter procedure. Spaying or neutering a sexually mature cat is important to prevent unwanted pregnancies, and it can also have positive effects on their health and well-being. Additionally, their adult teeth also start to grow and are usually completed when they reach six months.
• 4 to 9 months: They reach sexual maturity, which means they can impregnate or be impregnated if they were not spayed or neutered.
• 1 year+: A kitten grows to be a fully-grown cat.
• 2 to 4 years old: Adult cats become socially mature. They start to take some control over activities and social groups, which can lead to conflicts between male cats, between females, or between males and females.

The Life Cycle of Cats: From Kittens to Seniors

The feline lifecycle can be separated into five growth stages. Normally cats grow very quickly and get bigger after their first week of life. In the first week after adoption, it is normal when a kitten has doubled in size.

At this time cats have settled into their new life and normally are in very high health. The exact date varies from cat to cat but experts agree that an average cat reaches adulthood at twelve months.

A cat’s height reaches its peak between 2 and 8 years old (18 inches for most cats from paw to shoulder). And an average adult cat’s weight can reach about 10 pounds when fully grown.

Newborn to 3 Months Old:

This is the most rapid stage of a cat’s growth. Newborn kittens will go from being fully-dependent on their mom with their eyes still to closed to being energetic and somewhat chaotic kittens running and playing around at 3 in the morning.

Kittens will also experience a rapid yet healthy weight gain of about 0.25 to 0.5 pounds per week. And by the time they reach 10-12 months, they should have doubled their birth weight.

The first three months of a kitten’s life are also crucial for socialization. To avoid your kitten from being aloof, you should spend extra time cuddling and playing with him.

This is also why feral cats avoid humans because they didn’t have that human interaction while they were growing up.

From Three to Six Months:

Around this stage, kittens are going to sprout strong and sharp teeth. They'll also shift eyes from precious, baby blue color to adult color.

Also, during this time kittens will begin to build up muscle, and the little fat that decorates their belly will likely diminish.

Their baby teeth have fallen out of the jaw by the sixth month, so make sure your “Tooth Fairy” gives your furry friends the treats they need.

Sixth Month:

By the age of six months, your kitten will appear much older than its older sibling. A typical-sized cat will increase by one pound every month during maturity. Your cat's facial features would be more prominent during this time.

You can also start to transition your kitten from kitten food to adult cat food, though this could also depend on your cat's breed.

Some cats are still growing kittens during this time, such as Maine Coon cats and Ragdoll cats. So, for these larger breeds, you should still keep them on kitten food until they reach 2 years old.

An average cat's adolescent stage also starts during this age and will continue until their 12th month. Sexual maturation also happens during this time, though some cats become sexually mature as early as four months old.

That's why veterinarians advise that pet parents should have their cat spayed or neutered during this time or as early as four months old to prevent unwanted pregnancies.

Seventh Month:

Eventually, seven-month-old cats will demonstrate their sociability, and you can also expect longer naps as they get older.

Cats will even become more social together with humans in your house. Your cat will be enthusiastic to explore something but also gets sleepy easily.

Month Eight and Nine:

At this stage, your cat's confidence is likely at the highest level. Their paw coordination is expected to improve over this period. Clear out all areas in which your countertops are buried from harmful or – not removable materials.

About 9 months is almost enough for any normal kitten to evolve from mere tiny fur balls into the cute and slinky animals we know and love so much. How much growth your cat can take varies depending upon various other factors.

1 to 3 Years:

Your cat is an adult, and as mentioned earlier, most cats stop growing once they are 18 months old. Depending on your cat’s diet and proper nutrition, he should look like a healthy lean adult cat during this time.

3 to 6 Years:

This is the prime age for most cats, while other larger breeds continue to grow for a year or two.

7 to 10 Years:

Your cat becomes fully matured during this time, and he will be more laid back. Hence, proper nutrition and exercise can help prevent age related issues. You may also want to stop free feeding your cat.

11 to 14 Years:

These are the senior years, and as expected, older cats start to show age-related health issues. Your senior cat will also begin to slow down.

15+ Years:

This is a cat’s geriatric stage. You may notice age-related weight loss, and your cat’s fur will start to lose its former luster. Nonetheless, your cat will remain to be loving and always eager for snuggles and snooze time on your lap.

How Big Will Your Adult Cat Get?

Most experts recommend measuring the weight of a pet by the time he is four months old and multiplying that amount by two to get his approximate weight. Munchkin cats are amongst the smallest.

A Maine Coon can grow from 1 pound to 50 pounds. More bones might mean a bigger cat but this could not always be certain.

The weight that you can get will give you a ballpark idea, but you can also look at your kitten's parents to have a better picture in mind.

Factors Affecting How Fast Cats Grow

Several factors affect how fast a cat can grow. Aside from his breed, diet also plays an important role in a cat’s growth rate. Kittens are required to eat lots of calories before achieving proper size.

Age at the time of spaying or neutering also impacts the growth rate. Some diseases and bone deformities, such as degeneration and dwarfism can also stunt the growth of the afflicted cat.

Many shelter kittens are smaller in size than their rehomed counterparts. Studies show that a cat that gets spayed/neutered early in life grows taller than one that doesn't get it until adult life.

Other factors that can affect how fast cats grow and how big they can get are genetics, birth order, number of siblings, as well as the health of parents.