Guinea Pigs

How Big Do Guinea Pigs Get? Uncovering Their Growth Potential

Are you considering getting a guinea pig as a pet?

Well, before you make that leap, have you ever wondered just how big these adorable creatures can actually get?

From the petite to the magnificent, this article will uncover the secrets of guinea pig size, revealing the average weights and lengths for different breeds.

But size isn’t everything – we’ll also explore the recommended enclosure sizes and the essential role that proper space plays in their social well-being and overall health.

Get ready for a fascinating journey into the world of guinea pig growth!

how big do guinea pigs get

Guinea pigs can vary in size depending on their age, gender, and breed.

On average, adult guinea pigs measure between 8 and 12 inches long and weigh between 1.5 to 2.5 pounds.

Male guinea pigs tend to be larger and heavier than females.

The Rex breed is the largest, measuring up to 17 inches in length, while the American and Texel breeds are the smallest, measuring around 8 to 10 inches.

Overall, guinea pigs double in size within eight or nine weeks and stop growing around 14 months of age.

Providing a spacious enclosure is important for their well-being as they are social animals and need room for movement.

Key Points:

  • Guinea pigs’ size can vary depending on age, gender, and breed.
  • Adult guinea pigs are usually 8 to 12 inches long and weigh 1.5 to 2.5 pounds.
  • Male guinea pigs are generally larger and heavier than females.
  • Different breeds have different sizes, with the Rex breed being the largest (up to 17 inches) and the American and Texel breeds being the smallest (around 8 to 10 inches).
  • Guinea pigs double in size within eight or nine weeks and stop growing around 14 months old.
  • Guinea pigs need a spacious enclosure for their well-being, as they are social animals and require room for movement.


Did You Know?

1. Despite their name, guinea pigs are not actually pigs. They are rodents, specifically belonging to the family Caviidae.
2. Guinea pigs have an average lifespan of 5-7 years, but some have been known to live up to 10 years with proper care.
3. The size of guinea pigs varies depending on the breed. While most guinea pigs weigh between 1.5-2.5 pounds (0.7-1.1 kg), some larger breeds can reach up to 3 pounds (1.4 kg).
4. The largest recorded guinea pig ever weighed 3.5 pounds (1.6 kg) and measured 16.5 inches (41.9 cm) in length.
5. There is a long-haired breed of guinea pigs called Peruvian guinea pigs, and their hair can grow up to 20 inches (50.8 cm) in length if left untrimmed.

Average Size And Weight Of Male And Female Guinea Pigs

When discussing the size of guinea pigs, gender plays a significant role. Male guinea pigs generally have a larger size compared to females. On average, males weigh between 2 to 2.6 pounds (907 to 1,179 grams), while females weigh approximately 1.5 to 2 pounds (680 to 907 grams). This noticeable difference in weight contributes to variations in their overall size.

Growth Timeline And Size Measurements Of Guinea Pigs

Guinea pigs undergo rapid growth during their first few weeks of life. By the time they reach eight weeks old, they have completed a majority of their growth and nearly double in size. At this stage, they measure approximately 6 to 8 inches (15 to 20 cm) in length. By 16 weeks old, they are considered fully grown, with a length ranging from 8 to 10 inches (20 to 25 cm). This growth timeline offers a general understanding of the developmental progression in guinea pigs.

  • Guinea pigs experience rapid growth in their early weeks
  • At eight weeks old, they nearly double in size
  • Length measures around 6 to 8 inches at this stage (15 to 20 cm)
  • By 16 weeks old, they are fully grown, measuring 8 to 10 inches in length (20 to 25 cm)

“Guinea pigs experience rapid growth during their early weeks of life, almost doubling in size by eight weeks old.”

Size Variation Among Different Guinea Pig Breeds

It is important to note that there are various breeds of guinea pigs, and their sizes can vary significantly. The Rex breed is the largest breed, measuring up to 17 inches (43 cm) in length when fully grown. However, it is worth mentioning that the Rex breed is not officially recognized by the American Cavy Breeders Association, but it has its own Specialist Breed Club in the UK. On the other hand, the American guinea pig and the Texel breed tend to be the smallest, measuring approximately 8 to 10 inches (20 to 25 cm) when fully grown. Other guinea pig breeds have an average size of around 10 to 12 inches (25 to 30.48 cm) in length.

Notable Characteristics Of The Rex Breed

The Rex breed of guinea pig is widely known for its unique characteristics. It is the largest breed and boasts a distinct coat that is dense, short, and curly. This breed’s fur has a velvety texture that sets it apart from other breeds. Although not officially recognized by the American Cavy Breeders Association, the Rex breed has gained popularity and has its own dedicated Specialist Breed Club in the UK.

  • The Rex breed is the largest among guinea pigs.
  • They have a dense, short, and curly coat.
  • The fur of Rex guinea pigs has a velvety texture.
  • The breed is not recognized by the American Cavy Breeders Association.
  • The UK has a dedicated Specialist Breed Club for Rex guinea pigs.

    “The Rex breed of guinea pig stands out with its unique features and has gained a dedicated following in the UK.”

Size Guidelines For Guinea Pig Breeds

When considering the size of guinea pigs, it is essential to have some guidelines to ensure their comfortable accommodation.

  • Newborn guinea pigs are around 3 to 4 inches (7.6 to 10 cm) in length and weigh approximately 3½ ounces (100 grams).
  • As they continue to grow, they reach their full size within eight or nine weeks.
  • Adult guinea pigs generally measure between 8 and 12 inches (20 to 30 cm) in length and weigh between 1½ to 2½ pounds (680 to 1,200 grams).
  • However, some breeds can even reach weights of up to 4 pounds (1,800 grams) on average.

These guidelines offer a rough estimate of the size to expect from different guinea pig breeds.

Important: Ensure proper accommodation for guinea pigs based on their size.

Factors Influencing The Size Of Guinea Pigs

Several factors influence the size of guinea pigs. Age, activity level, gender, and breed all play a role in determining their size and weight. Guinea pigs tend to grow rapidly during the first few months of their lives, with growth slowing down after the initial spurt. Additionally, males are generally larger and heavier than females. The breed of the guinea pig also significantly influences its size. Providing a healthy diet and adequate exercise can positively impact the growth and size of guinea pigs.

Enclosure Size Recommendations For Guinea Pigs

Guinea pigs require more room to roam compared to other small pets such as hamsters or gerbils. It is important to provide them with an appropriate enclosure size to meet their needs. The minimum height for an enclosure should be 12 inches (30 cm). For one guinea pig, the recommended minimum enclosure size is 30 by 36 inches (76 by 91 cm), but it is preferable to have a size of 30 by 50 inches (76 by 127 cm). If you have two guinea pigs, the minimum recommended size is 30 by 50 inches (76 by 127 cm), with the preferred size being 30 by 62 inches (76 by 157 cm). Offering sufficient space is crucial to ensure their movement and prevent obesity. Moreover, large enclosures can help reduce the risk of fighting among guinea pigs.

Safety Considerations When Housing Guinea Pigs With Other Pets

If you plan on housing guinea pigs with other pets, it is important to consider their safety. Before introducing your guinea pigs to any other animals in your household, carefully check the enclosure for potential hazards. Provide a safe and secure space for your guinea pigs, ensuring that they are protected from any potential harm. This is especially crucial if you have larger pets, such as dogs or cats, as their natural instincts may pose a risk to the smaller guinea pigs. By planning and taking necessary precautions, you can ensure a harmonious and safe living environment for all your pets.

Guinea pigs come in a range of sizes and weights depending on factors such as gender, breed, and growth stage. Male guinea pigs tend to be larger than females, and the Rex breed is the largest of all. Different breeds have varying size averages, with the smallest guinea pig breeds measuring around 8-10 inches (20-25 cm) when fully grown. It is important to provide an appropriate enclosure size for guinea pigs, as they require ample space for movement and social interaction. By considering these factors and providing a safe and spacious environment, guinea pig owners can ensure their beloved pets thrive and reach their full growth potential.


What is the largest breed of guinea pig?

While the Rex guinea pig is indeed one of the largest breeds, reaching an impressive size of 8 to 18 inches, there is another breed that surpasses even that. Known as the Skinny pig, it may lack a luxurious fur coat, but it compensates with its substantial size. These unique guinea pigs can grow to be quite large, making them an intriguing and noteworthy addition to any guinea pig enthusiast’s collection. So, if you’re seeking the largest breed of guinea pig, look no further than the delightful Skinny pig.

Do guinea pigs like to be held?

Guinea pigs can be quite affectionate and generally appreciate being held and cuddled. However, it’s important to note that each guinea pig is unique, and their personality and preferences may vary. Some guinea pigs may instantly enjoy being held, while others may require a few days or even weeks to feel comfortable in their new environment. Patience and allowing them time to acclimate to their surroundings will help foster a bond between you and your furry friend, creating an environment where they are more likely to enjoy being held and petted.

How long does 1 guinea pig live?

On average, guinea pigs have a lifespan of five to seven years, which exceeds the life expectancy of several other small pets, including hamsters, gerbils, mice, and rats. Guinea pigs enjoy a relatively longer lifespan compared to these animals, typically living several years longer. These social and lovable creatures bring joy and companionship to their owners for a considerable period of time.

How many guinea pigs should be in one cage?

To ensure the well-being and social interaction of guinea pigs, it is recommended to have at least two in one cage. Each guinea pig should ideally have a minimum of 7.5 square feet, or approximately 30″x 36″, but providing a larger enclosure is even more beneficial. Given their highly social nature, sharing a living space with a compatible companion helps to promote their overall happiness and mental stimulation.

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