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How Big Will My Kitten Get, & Which Factors Affect It?

From tiny little kittens that can fit into the palm of your hand to adult cats that might barely be able to fit in your lap, cats come in all sizes. There are cats like the Munchkin and Singapura, made to be tiny and maintained at that size. Then you have the giants of the cat world, like the Maine Coon.

Knowing how big your kitten could be is essential for several reasons. You might only have space in your home for a small to medium-sized cat or the budget to feed a smaller cat. Keeping track of their size is also a great way to keep track of their health.

We’ll take a look at indicators in kittens for what size they might be as an adult. We also give you a brief overview of what can affect a kitten’s size as they reach adulthood. This way, you can do what is best for them to keep them healthy.

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How Do You Tell How Big a Kitten Will Get?

 kitten laying _Sheila Fitzgerald_Shutterstock
Image Credit: Sheila Fitzgerald, Shutterstock

When it comes to puppies, you can often estimate their adult size by the size of their paws. Unfortunately, that method is not quite as reliable when it comes to kittens. Instead, the best indicator is their breed. If you adopted a kitten and aren’t sure of their breed, then you can take a look at their other body parts to figure it out.

Cat Breed

Most cat breeds are well-established. Because of this, the cats’ sizes and demeanors are often quite similar throughout the entire breed. If you know your kitten’s breed or mix, you should be able to determine how big they will be.

For example, some of the most popular cat breeds and their sizes include:
  • Domestic Shorthair: 6 to 16 pounds
  • Maine Coon: 7 to 25 pounds
  • Siamese: 8 to 10 pounds
  • Ragdoll: 12 to 20 pounds
  • Russian Blue: 7 to 15 pounds

Cat Legs & Tail

kitten is playing with a ball_Chendongshan_shutterstock
Image Credit: Chendongshan, Shutterstock

Another indicator of a kitten for its eventual adult size is its back legs. If your kitten has tall back legs, it generally means they will be a larger cat. They will grow into these legs steadily, most often when they hit around 6 to 9 months old.

Although tails aren’t always proportionate to a cat’s body size, they are another good indicator. By 4 months old, your cat’s tail is the size that it will be in adulthood. That often means they have to grow into their tail. Using their age to determine their eventual size can work as well. When a kitten hits 5 months old, they have reached approximately half the weight that they will be as a healthy adult.

By the time a kitten is about 9 months old, they will typically be adult size. However, larger breeds will continue to grow for several more months.

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How to Tell How Big Your Cat Will Get

blue point ragdoll kittens_Liliya Kulianionak_Shutterstock
Image Credit: Liliya Kulianionak, Shutterstock

The size of a kitten could change dramatically, depending on its breed. So, it’s challenging to give you an approximate size of how big they should be as they grow older. However, for each breed, you can use charts to figure out how much your kitten should weigh at their age.

If you are unsure of your kitten’s age because you rescued a stray, you can talk to your vet. Kittens have the best age markers because they develop in distinctive ways. Your vet can check these to determine how many weeks or months old they are.

There is nothing that you can do to change the size of your adult cat beyond using cruel methods that any pet owner needs to avoid. The primary factor that affects a kitten’s size as they grow is diet. Spaying and neutering might also play a role, but differently than what you might expect.

Cat Diet

kitten not eating_Happy monkey, Shutterstock
Image Credit: Happy monkey, Shutterstock

A kitten’s diet has the most substantial impact on its size. If they are under or overfed, their weight and size will be disproportionate to what they should be. To maintain proper development, your kitten needs plenty of protein and a healthy source of calories.

Before your kitten reaches 9 to 12 months of age, they should eat kitten food. This food should have a high protein content. It should also have the nutrients usually found in a mother cat’s milk to encourage brain development. It should also be slightly higher in fat, using healthy animal-based fat sources for proper digestion.

Overfeeding your kitten is just as cruel as underfeeding your kitten because their bodies are not made to handle fat well. A cat’s overall frame should look like an hourglass when you look at them from above. If you have a long-haired cat, you might need to feel for that.

The Truth About Spaying & Neutering

neutering cat_Simon Kadula_Shutterstock
Image Credit: Simon Kadula, Shutterstock

Now we need to bust a myth: There is an idea that spaying or neutering your kitten will make them into a fat adult once they come of age. That is the opposite of true.

Cats that get spayed or neutered do experience a hormonal change. But instead of making them bigger, it often influences them to be a smaller size. They are often more slim and trim than anything.

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Although it might be challenging to determine how large your kitten will be as an adult, you can use things like their legs and tails to help you figure it out. If you know what the breed is, looking up averages is the best way to determine what they will be in a year. It is up to you as their owner to ensure that they get a complete diet of kitten food so they can grow into the healthy adult that they are meant to be.

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Featured Image Credit: Tom Pingel, Shutterstock