Catster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

How Big Does a Cornish Rex Get? Vet Reviewed Weight & Growth Chart

By Ashley Bates · Reviewed & fact-checked by Dr. Chyrle BonkVet Approved
Dr. Chyrle Bonk
Reviewed & Fact-Checked byDr. Chyrle BonkDVM (Veterinarian)
On top of healing animals and writing for veterinary publications, Dr. Chyrle Bonk owns a small cattle herd! When she’s not busy with those things, she can be found somewhere in the Idaho outdoors with her husband and two kids.View authorThe information is current and up-to-date in accordance with the latest veterinarian research. Read about our vets
Share
close up of a cornish rex with green eyes

The Cornish Rex is a cat breed that is extremely distinct. Like other animals with the rex gene, they are covered in a layer of downy, soft, curly, or wavy fur. They have long, slender bodies and narrow faces.

If you were interested in the Cornish Rex, you might wonder exactly how large these cats get. A full grown Cornish Rex is expected to weigh 6-10 pounds and measure 8-12 inches. In this article, we will go over their particular growth patterns and other details about what to expect when you own one of these fascinating felines.

divider 1 paws

Cornish Rex Overview

The Cornish Rex is a genetic anomaly. In Cornwall, England, during the 1950s, a kitten was born that would be the platform for all Cornish Rex that exist today. This kitty was very different from his brothers and sisters, having a downy, curly coat.

Luckily, Nina Essenmore was the one who found the kitten. She was very knowledgeable about the rex gene chain because she raised rex rabbits. She worked diligently alongside professionals to develop the Cornish Rex breed, and we’re certainly glad she did!

The Cornish Rex is one of the most unique-looking felines to exist today. Plus, it has a sound temperament and excellent companionship potential.

Cornish rex cat sitting on the grass
Image Credit: Rita_Kochmarjova, Shutterstock

Cornish Rex Size and Growth Chart

The Cornish Rex is a medium sized breed that looks rather large due to their height, which is between 8-12 inches. However, these cats are incredibly light on their feet, giving them a lanky appearance. Males tend to be larger than females.

AgeWeight
Newborn1.8–5.3 ounces
2 Weeks5.3–8.8 ounces
3 Weeks12.3–15.9 ounces
4 to 8 weeks1.4–2 pounds
9 to 12 weeks3–3.5 pounds
12-16 weeks4–4.5 pounds
16-20 weeks5–5.5 pounds
6 months6–6.5 pounds
12 months6-10 pounds

When Does a Cornish Rex Stop Growing?

This particular breed stops growing between the ages of 9 and 12 months of age. Certain factors, such as genetics, diet, and environment, play a role in when growth will end.

divider 1 paws

Factors Affecting the Size of Cornish Rex

Several factors can affect the size of your Cornish Rex. Here are some things that can determine ultimate size.

Cornish Rex kitten
Image Credit: Elena Loginova, Shutterstock

Diet

A high quality diet is vital, especially during your kitten's growing months. They need proper nutrition to nourish their growing bones, muscles, and organs as they develop. If a kitten is malnourished, it can cause a reduction in growth.

Malnutrition as a kitten could make them much smaller as adults than they would have been had they had the appropriate care.

On the other hand, if you give your Cornish Rex far too much to eat regularly, the extra calories could quickly lead to becoming overweight, which may snowball into obesity and a whirlwind of other health issues. If you have any questions on the amount you should feed a Cornish Rex kitten, speak to a vet.

Genetics

Genetics plays a very significant role in ultimate size. For example, if you have two Cornish Rex parents on the smaller end of the scale, they will likely produce smaller kittens.

If one of the parents is particularly small for the breed, and the other is quite large, you could have a random mix of sizes among kittens of the litter. Oppositely, it goes without saying that if both Cornish Rex parents are reasonably large for the breed, their kittens should also be larger when fully grown.

Health Conditions

Certain health conditions can cause delayed growth in cats. For example, kittens that are very sick or weaned early from their mother may grow at a slower rate than healthy kittens. There are even some rare genetic issues that can result in a smaller size, such as dwarfism.

divider 1 paws

Ideal Diet for Maintaining a Healthy Weight

A Cornish Rex’s weight can be difficult to manage, especially given their small size. To keep them at a healthy weight, especially after a spay or neuter surgery, here are some tips on how to manage.

Portion Control

You should always demonstrate portion control when dishing out your cat's meals. Each bag will have serving recommendations based on your cat's current weight and weight loss goals (if any).

Giving them the correct portions will help ensure they are getting the appropriate amount of nutrition and calories at every meal. They are a guideline however and should be used as a starting point. Some individuals will need more or less than the guidelines to keep in a healthy weight range. Also, this will help you monitor their appetite.

Exercise

It may be difficult to exercise a cat, but exercise plays a large role in overall health, including maintaining a healthy weight. You may get your cat to exercise by encouraging play with interactive toys, cat trees for climbing, or outside time if possible.

Regularly Attend Vet Visits

Taking your cat to the vet regularly will really help with weight management. Your vet will be the first to tell you if your cat should go on a diet or if they need more calories. Also, dietary needs can change based on a change in health status or stage of life.

vet checking up the cat
Image Credit: Maria Sbytova, Shutterstock

How to Measure Your Cornish Rex

Measuring your cat is important for quite a few reasons. First of all, it will help you know if their growth is on track. However, knowing how to measure your cat could be nice for other reasons, such as purchasing cat-specific products.

For example, if you’re buying a cat carrier, you want to know that it’s a suitable size for your feline companion. Or, maybe, you want to buy a harness and leash to take your cat on adventures. Their appropriate measurements will ensure a proper fit and avoid lengthy returns or exchanges.

  1. Use a flexible measuring tape.

  2. Measure the neck around the part where the collar would naturally sit.

  3. Measure the chest behind the shoulder and armpits and around the back to check the broadest circumference.

  4. For length, measure from the neck's base to the tail's base.

  5. For height, measure from the ground to the top of the shoulder.

  6. For weight, place your cat directly on a scale. Alternatively, you can weigh yourself, then weigh yourself holding your cat, and subtract your weight from the total weight to find your cat’s weight.

You are free to use this image but we do require you to link back to Catster.com for credit
divider 1 paws

Conclusion

Now that you know what to expect from a Cornish Rex‘s growth, are you still interested in owning one of these fun-loving kitties? We're sure you won't be disappointed since these cats have lovely personalities and extraordinarily unique features.

Remember, if you want to purchase a Cornish Rex kitten, check for reputable breeders in your area. Most breeders will work under the approval of cat associations to ensure buyers receive a quality kitten.

Sources

Featured Image Credit: Jenni Ferreira, Shutterstock

Expert cat care, straight to your inbox

Vet-reviewed advice, behavior tips, and the best of Catster. Free, and you can unsubscribe anytime.

By signing up, you agree to our Terms & Conditions and Privacy & Cookies Policy.

Ashley Bates
Authored by

Ashley Bates

Join the conversation

Ask a question, share your story, or send private feedback.

Rate this post
Required to post. Only our editors see your rating.
Who should see this?

A human reviews every comment before it appears. Your email is never published.

Cornish Rex Cat: Breed Info, Pictures, Traits & Facts

Cornish Rex Cat: Breed Info, Pictures, Traits & Facts

The Cornish Rex cat is a unique and energetic cat that fits in most families. It was first discovered in Cornwall, England, and has since won the affection of…

Christian Adams
By Christian Adams ·
How Big Do Oriental Shorthair Cats Get? Vet-Reviewed Size & Growth Chart

How Big Do Oriental Shorthair Cats Get? Vet-Reviewed Size & Growth Chart

The Oriental Shorthair cat is svelte and elegant, and just like their Siamese ancestors, they are athletic, lively, and intelligent. It’s easy to imagine these…

Kerry-Ann Kerr
By Kerry-Ann Kerr ·
Cornish Rex Lifespan: How Long Do They Live? Vet-Reviewed Facts

Cornish Rex Lifespan: How Long Do They Live? Vet-Reviewed Facts

In 1950s England, a random genetic mutation produced a kitten with an unusual curly coat. From this single kitten, the Cornish Rex breed was born. Known for th…

Elizabeth Gray
By Elizabeth Gray ·
10 Vet-Verified Cornish Rex Facts That Cat Lovers Should Know

10 Vet-Verified Cornish Rex Facts That Cat Lovers Should Know

Cornish Rexes are known for their charming appearance and personality. These unique-looking cats are sure to catch one’s eye with their curly coats, bat-like e…

Jessica Kim
By Jessica Kim ·

6 Types of Cornish Rex Cats: Colors, Breeds & Patterns (With Info & Pictures, Vet-Reviewed)

Cornish Rex cats are incredible cats. They tend to be friendly cats that love their humans, and will generally get along with other pets as well as strangers,…

Christian Adams
By Christian Adams ·
6 Types of Cornish Rex Cats: Colors, Breeds & Patterns (With Info & Pictures, Vet-Reviewed)

Cornish Rex Price: What They Cost in 2026

The Cornish Rex is a domestic breed of cat that has unusual fur. Instead of an outer coat, a middle layer, and an undercoat, like most other cat breeds, they h…

Rachael Gerkensmeyer
By Rachael Gerkensmeyer ·
Cornish Rex Price: What They Cost in 2026

How Big Does an Abyssinian Get? Average Weight & Growth Chart

With a lean, elegant look, the Abyssinian cat strongly resembles the cat statues of Ancient Egypt. They’re a striking breed with exotic gold and cinnamon coats…

Catster Editorial Team
By Catster Editorial Team ·
How Big Does an Abyssinian Get? Average Weight & Growth Chart

Do Cornish Rex Cats Shed a Lot? Vet-Verified Facts & Grooming Tips

Cornish Rex cats are lovable short-haired kitties known for their playful persona and rippling soft coat that lacks coarse guard hairs. In a certain light, it…

Codee Chessher
By Codee Chessher ·
Do Cornish Rex Cats Shed a Lot? Vet-Verified Facts & Grooming Tips

How Big Will My Kitten Get & Which Factors Affect It? Vet-Verified Facts & Tips

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…

Christian Adams
By Christian Adams ·
How Big Will My Kitten Get & Which Factors Affect It? Vet-Verified Facts & Tips

How Big Will My Egyptian Mau Get? Average Size & Growth Chart

Egyptian Maus make their superior athleticism and energy apparent at a young age, and many owners wonder how much of a handful they’ll become as adults. How bi…

Christian Adams
By Christian Adams ·
How Big Will My Egyptian Mau Get? Average Size & Growth Chart

How Big Do Maine Coons Get? Average Size Chart & Vet-Reviewed Care Tips

One of the most magnificent domestic cats is the Maine Coon, primarily because of their stunning large body and fluffy coat. These cats are incredibly affectio…

Jana Blagojevic
By Jana Blagojevic ·
How Big Do Maine Coons Get? Average Size Chart & Vet-Reviewed Care Tips

How Big Do Munchkin Cats Get? Vet-Reviewed Average Weight & Growth Chart

Munchkin cats are generally considered to be friendly, cheerful, affectionate companions. They have unusually short legs which is due to a genetic mutation cau…

Lorre Luther
By Lorre Luther ·
How Big Do Munchkin Cats Get? Vet-Reviewed Average Weight & Growth Chart

Love Cats? So Do We! Join the Catster Community

Stay informed with expert cat care insights delivered straight to your inbox! Discover professional guidance on feline behavior, feeding tips, trusted product picks, and much more.

You may opt-out at any time. View our Privacy Policy for more information.

The Catster site on a phone