Chinchilla Growth Stages: Weight, Body Size, & More

Chinchillas are one of the few rodents humans willingly bring home. They are luxuriously furry, adorably playful, and so tiny – you can literally fit them in your pocket!

But do they always remain that small?

Nope! Chinchillas grow quickly. They grow in size and pack some grams every other month until they are fully grown.

So, how big do chinchillas get? And what are the chinchilla growth stages?

In this article, we’ll understand more about how big your fuzzy friend can get and how. It’ll help you make adjustments to your chinny’s lifestyle so he can stay healthy and happy.

Key Takeaway:

Chinchillas have five growth stages. A baby chinchilla starts his journey at 1-2 inches and an average weight of 25-80 grams (0.8-2.8 oz.). A fully-grown chinchilla can measure up to 9-19 inches and weigh between 450 and 907 grams (15.8-32 oz.), depending on the breed. Female chinchillas are heavier than male chinchillas.

Do both breeds of chinchillas grow the same? When are chinchillas full-grown?

Let’s get you all the answers you want. Scroll, chinchilla parents!

chinchilla growth

Chinchilla Growth Stages

Do you ever look at your little munchkin and wonder, “How big can this little guy get? Or is this the max size I will see?”

Chinchillas have five growth stages. Over time, they go from a bun in the oven to full-grown fuzzsters – always maintaining their cuteness!

As a responsible parent, you must understand these stages so you can make sure your chinny meets his growth milestones, stays healthy, and lives a long life. Yep, it's all linked.

So, what are these five stages?

Gestation Period

The first stage of chinchilla growth happens inside mama chinchilla’s womb. Over 110-115 days, your little furball grows and prepares to come into the world. The medical term for this period is gestation.

How many babies can I expect?

A mother chinchilla will give birth to 2-4 babies. Though the average brood size is two, a litter can have 3 or 4 kits.



Yep, kits! That’s what you call newborn chinchillas.

Baby chinchillas weigh around 25-80 grams (0.8-2.8 oz.) and size up to 1-2 inches in length. Unlike other mammal babies, chinchillas come curled up with a full coat of fur. As soon as they're out, they'll look around with their big, beady eyes and be able to hear their mama's voice.

Interestingly, baby chinchillas get to their feet quicker than other mammals. Your little fuzzball will hop and jump around by the end of his first day in the world. 

However, this doesn’t mean you can separate the little one from his mommy. He still needs to feed and take shelter in her burrow.

How long should I leave the kit with his mom?

A kit must stay with his mom for 8-12 weeks. It gives him enough time to get attached to his mommy and learn the ropes.


After 8-12 weeks, mommy chinchilla will reduce the time she spends nursing her kits. This is when the kits become weanlings.

If there are any male kits, you can separate them at this stage. Keep them in another cage with other weanlings of the same sex. As for the female kits, they can stay with their mommy forever – if they get along!

How does a young chinchilla react to separation?

No more mom milk, no more warm burrows to sleep in – it’s a rocky transition. It is why weanlings lose some baby chin chub and appear less fluffy. But don’t worry; feed him the right food, and he’ll bounce back.


This is the chinchilla teenage phase. It lasts till a chinchilla is 9-12 months old. During this stage, a chinchilla is learning to be independent, trying out his newfound strength and agility.

Juvenile chinchillas can also be mated. A male chinchilla becomes sexually mature at 8 weeks of age. In contrast, a female chinchilla will become sexually mature at around 10-12 months old.


Adulthood is the final stage of growth in chinchillas. This is when a chin hits the year mark. Some chinchillas stop growing at this age, but most continue to grow for a few more months.

Since pet chinchillas live for an average of 20 years (depending on the care you provide), a year-old chin isn’t really an oldie. His life has just begun. He’ll be active for many more years to come.

chinchilla stages

How Big Do Chinchillas Get?

How big can a chinchilla grow?

Right from birth, chinchillas are a step ahead of other pet rodents. They are born with a full coat of fur (unlike hamsters, which are born hairless), have full vision and hearing ability, and hit the ground running. All that with a tiny, tiny bod.

But chinchillas don’t stay that tiny for long. They grow a little every few weeks.

The chinchilla growth table below has more details.

Chinchilla Growth Table

Chinchilla AgeChinchilla Size
1 month old1-2 inches
2 months old2-3 inches
3 months old8-10 inches
6 months old8-10 inches
9 months old11-15 inches
12 months old15-19 inches

How big is a chinchilla when full-grown?

Depending on the breed and gender, a full-grown chinchilla can be 15-19 inches long.

Which Chinchilla Breed is Bigger?

There are two types of chinchilla breeds – long-tailed chinchillas and short-tailed chinchillas.

As the name suggests, short-tailed chinchillas have, well, short tails. Their bodies are rounder and bulkier, and their fur is lusciously thick. These guys live higher up in the Andes Mountains.

Long-tailed chinchillas, on the other hand, have longer tails with a more slender body type. Their fur is slightly thinner, but they still look great! They prefer hanging out in the foothills of the Andes, hence the less dense fur.

So, which of the two is bigger?

The table below will make it easier for you to compare which breed grows bigger:

Chinchilla Breed Growth Table

Chinchilla BreedAverage SizeAverage Weight
Long-tailed Chinchilla9-15 inches1-2 pounds
Short-tailed Chinchill12-18 inches2-3 pounds

Note: Since short-tailed chinchillas are nearly hunted to extinction for their dense fur, your pet chinchilla most likely descends from the long-tailed breed.

Female Vs. Male Chinchillas

What about gender? Does a female chinchilla differ in size compared to a male one?

Well, if you look at size in terms of length, there isn’t much difference between a female and a male chinchilla.

But when it comes to weight, female chins are heavier. They can weigh up to 450-750 grams (15.8 to 26.5 oz.) on average. Males, on the other hand, typically stay lighter at 400-500 grams (14 to 17.5 oz.) on average. It is why female chins appear bigger than male chins.

Note: These stats are for long-tailed chinchillas.

long tailed chinchilla

Pet Vs. Wild Chinchillas

Wild chinchillas live at the higher altitudes of the Andes Mountains and are tough guys. But because they have shorter lifespans in the wild due to predators, weather conditions, and limited food resources, these cuties barely make it to their full size.

Do wild and pet chinchillas differ in size? How big are chinchillas in the wild?

Yep, there’s a size difference. Pet chins are bigger. They are specifically bred to be about double the size of wild chinchillas.

However, on average, wild chinchillas reach up to 9-14 inches in length with 3-6 inch long tails. Their weight is somewhere between 1 and 3 pounds.

When Do Chinchillas Stop Growing?

When are chinchillas full-grown?

If you’ve just welcomed a new chin into your home, knowing when he’ll be fully grown is important. It will help you plan and prepare for any extra space that you may need in the future.

Chinchillas are full-grown by 8 months of age. However, most of them continue to grow till 18 months of age. Their growth slows down at this point, and they stop growing completely at around 2 years old.

What Changes as Chinchillas Grow?

Aging isn’t any different for chinchillas. Their bodies change and adapt according to their diet and lifestyle as they age.

Do all chinchillas age at the same rate?

Nope! Some start looking old only at 9 years while others maintain their active and youthful looks till 10 to 12 years.

Also, chinchillas tend to become less active and quiet with age. Some also lose weight and become frailer. But with a good diet and a healthy lifestyle, you can slow the aging process and keep your pet looking young for many years.

Making Sure Your Chinchilla Grows Well

If you want your pet chinny to grow to his full size without getting overweight, here’s what you need to do:

  • Get a Big Enough Cage – The ideal chinchilla cage size for one chinchilla is 4x4x3 ft. If you have two or more chinchillas in a cage, you’ll need 20 square feet of floor space for each.
  • Provide a Balanced Diet – Hay and chinchilla pellets should form the basis of your pet’s diet. Avoid foods with high sugar or fat content. Make sure they always have access to fresh and clean water.
  • Get Them to Exercise Regularly – Maintain your chinchilla’s weight and give them enough exercise by providing a play area outside the cage. A wheel is also good for their physical activity.
  • Visit the Vet – Schedule regular health checkups with your vet to ensure your pet isn’t suffering from any underlying medical condition.

Unveiling the Fluffy Evolution: Chinchilla Growth Stages Explained

Chinchillas are popular pets among rodent lovers. But before you bring one home, you might wonder, “How big do chinchillas get?” After all, you want to provide your pet with the best living conditions possible.

Thanks to this article, we know that a baby chinchilla can weigh between 25-80 grams (0.8-2.8 oz.)and be 1-2 inches long. As for adults, they can get as big as 19 inches and weigh between 1 and 3 pounds, depending on their breed and gender.

Did you find this article helpful?

At Oddly Cute Pets, we always strive to provide our readers with accurate and reliable information so that they can give their furry friends the best care possible. If you have more queries about chinchillas, check out our other articles on the website.

Happy chinchilla parenting!

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