How Much Should A Guinea Pig Weigh?

Share on facebook
Share on google
Share on twitter

Guinea pigs can live long lives – even up to 9 years. With proper care, many guinea pig owners are able to extend their pets’ lives – going beyond their normal lifespan. But properly caring for a guinea pig has its own challenges, especially when it comes to the critter’s health.

A healthy guinea pig would be distinguishable when you look closely at its eyes, nose, fur, and bottom part. 

One of the most obvious determinants of health would be the guinea pig’s own weight. An increase or decrease in weight says a lot about a guinea pig’s condition. With this being said, exactly how much should a guinea pig weigh?

animal weight balanca

Why It Matters?

Because they are prey animals, guinea pigs have become adept at hiding what they’re feeling so as not to show any signs of weakness that their predators would surely take advantage of. This would include whatever pain and weakness that they may feel. While guinea pigs have already come far from their wild origins, they have kept this trait even through their domestication.

Their ability to mask their emotions makes it difficult to assess the true conditions of guinea pigs. Thankfully, their appearance isn’t something they can easily hide, especially their weight. Monitoring their weight could help you prevent your pet from becoming overweight or underweight.

Changes in weight could become dangerous for guinea pigs. Here’s why:



When a guinea pig becomes overweight, or worse, obese, it can damage its overall health. This is because guinea pigs’ bones aren’t designed to handle too much weight. Not only that, the added weight makes them highly susceptible to arthritis, high blood pressure, and heart disease.

This could ultimately shorten the guinea pigs’ lifespan. Since guinea pigs are naturally carnivores and eat little fat, becoming overweight is quite uncommon for their kind. If you have an overweight or obese guinea pig, you can get it into a reducing diet.


If a guinea pig becomes underweight despite giving it a well-balanced diet, you should take it immediately to a veterinarian because chances are, parasites have infested its body or it is suffering from a genetic disease.

cute american guinea pig

Ideal Guinea Pig Weight

Guinea pigs can grow from 8 to 11 inches long and their weight should always be relative to their size. 

While the ideal weight of a guinea pig can best be determined by its size, males should weigh around 900 to 1200 grams or 1.98 to 2.65 pounds. The average guinea pig weight for females, on the other hand, is around 700 to 900 grams or 1.54 to 1.98 pounds.

Guinea pig weight can be affected by several factors including sex, breed, and even litter size wherein the bigger the litter, the lighter the pups. When they are born, expect guinea pig pups to be somewhere between 60 and 120 grams. Usually, the smallest pup in the litter should be given close monitoring because it is the most at risk of not surviving.

As they grow up, you may notice them gaining weight at an incredible rate – about 30 to 50 grams per week. However, as they reach maturity, you would find the weight gain slowing down or halting. When they fully mature, males (boars) are often 20 to 25 percent bigger than females (sows).

Monitoring Guinea Pig Weight

Constantly keeping track of your guinea pig’s weight is important because conditions like malocclusion, bloat, anorexia, and digestive problems are all too common with these animals. Using a digital weighing scale, monitor your guinea pig’s weight at least once a week.

Placing the guinea pig in a bowl during the weighing process can help if your pet is moving a lot. Just don’t forget to subtract the weight of the bowl so you don’t get inaccurate readings.

If you think your guinea pig isn’t feeling too well or is not eating normally, keep track of the critter’s weight twice a day.

Sizing Guinea Pigs

Sizing your guinea pigs is a good way to make sure your pet is in an ideal weight. Typical guinea pig sizes would include: very thin, thin, normal, overweight, and obese.

  • Very Thin

One of the defining characteristics of a very thin guinea pig is their prominent ribs. Each rib could be felt easily along with the spine and the hips. Since they are very prominent and visible, even with the slightest touch, you’d be able to feel them.

Furthermore, the spine would appear hunched and there is also a visible under-abdominal curve. A very thin guinea pig would be 20 percent below the ideal body weight.

If your pet falls under this category, there is no doubt that it is underweight. Consult your veterinarian to find out any underlying medical causes as to why the guinea pig is underweight. If your pet is deemed unhealthy, the vet may advise a dietary and lifestyle change for your guinea pig.

  • Thin

Unlike the first size category, thin guinea pigs do not have prominent rib cages, spine or hips. However, if you touch them, they will be easily felt. There will still be an abdominal curve but it would be less than that of a very thin guinea pig.

If your pet is thin, there is a chance that it naturally has a lean physique or it is underweight. Just to be sure you can consult with your veterinarian about your pet’s size. Usually, guinea pigs of this category weigh around 10 to 20 percent below the average.

  • Normal

This is the ideal guinea pig size. When your pet is of a normal or ideal size, there will be no prominent rib cage, hips or spine. The ribs couldn’t be felt individually but the same cannot be said with the hips and spine. There won’t be an abdominal curve and the chest would be narrower than the bottom area.

If your pet is of a normal body size, it can help extend the guinea pig’s lifespan. However, you also bear the responsibility of maintaining this body size. To do that, you would need to closely monitor the guinea pig’s weight and make sure it eats a stable healthy diet.

  • Overweight

When a guinea pig is overweight, it is usually 10 to 15 percent above the ideal weight. Since there is more weight, the ribs would be more difficult to locate while the hips and spine would not be easily felt. Furthermore, you may notice that an overweight guinea pig’s feet will not always be visible.

An overweight guinea pig is at risk of having a shorter life along with medical conditions like heart disease, arthritis, and high blood pressure among others.

Just like with underweight guinea pigs, you may need to consult with a vet in order to determine the cause of your pet’s excessive weight. This is usually caused by an unhealthy lifestyle but there is also a possibility that your guinea pig is suffering from a medical condition.

The vet would guide you on how to proceed with reducing the weight of your pet guinea pig.

  • Obese

The heaviest of body types, guinea pigs suffering from obesity are often 15 to 20 percent above the ideal weight. Obese cavies have ribs, hips, and spines that are unable to be felt unless dealt with pressure which may harm your pet. The body shape is also not distinguishable and its belly may be touching the floor causing the feet not to be seen.

Obesity is a dangerous condition and makes the guinea pig highly susceptible to numerous health complications. This is why you should seek professional help immediately if you don’t want to lose your pet prematurely.


Domesticated guinea pigs rely on their owners to survive and the lifestyle they build is mainly influenced by the decisions their pet parents make for them. Because of this, you would need to be responsible for raising your pet. To do this, you have to set a proper diet for them that would include all the food they need to meet their nutritional requirements and making sure that you do not overfeed or underfeed them.

You even need to play a big role in their physical activities; providing them with opportunities to stay active. Furthermore, it would be your job to monitor their health. If you notice any fluctuations in your pet’s weight, you have to find out their causes or take the animal to the vet to help you out.

Guinea pigs live fairly long lives but only if you raise them right.

Carlye Yancey
Carlye Yancey

Between internships, volunteering, and paid jobs over the last 4 years, I have pretty much-gained experience with domesticated animals. Currently being in school for my veterinary technology degree, I spend my leisure time with 3 critters that I own.

Leave a Reply

Close Menu