Table of Contents
Guinea Pig Weight – Introduction
As with a majority of mammals, Guinea pig weight is an excellent indicator of overall health and well being. It is therefore important to monitor your Guinea pigs weight from birth. This will help ensure your buddy is developing and growing as expected into a healthy and happy cavy.
By continuous weight monitoring, you will be able to pick up anything out of the ordinary and tackle issues early. Whether it be weight loss or gain, this guide has all the important facts about Guinea pig weight. What to look for, how to weigh your piggy and methods to track weight continuously.
Why is the weight of my guinea pig important?
The weight of your Guinea pig is an important indicator of your pet’s health. Monitoring and recording weight from birth will help you check that your piggy is getting the right amount of food, nutrients, and vitamins, and developing into a normal healthy piggy.
Sudden changes in weight can be an indication of underlying health issues. So having this information on hand allows us to identify and deal with conditions at an early stage. Guinea pigs are born survivors, so naturally they will not often show signs of illness or weakness, which is why their weight is such a useful metric.
We’ve all been known to spoil our pets once in a while. But are we feeding them too much? Weight is a great way of helping us maintain healthy and balanced diets, and lets us know that maybe we are giving our p
What is the average weight of a guinea pig?
Weight is very much dependent on maturity in the Guinea pig world.
During infancy, when your piggy will developing rapidly, it is common to see a weight increase of around 20-30g a week.
This can happen in bursts, so do not be alarmed if your piggy doesn’t hit that number every week.
Weekly monitoring is useful during this stage to make sure there is at least a little weekly weight gain until the growth rate slows down around 9-12 months when your Guinea pig will be more or less fully grown.
On average, mature male Guinea pigs range from around 900-1500g (2-3lbs).
Mature Female Guinea pigs average weight is a little lighter around 600-1200g or 1.5-2.5lbs.
If your piggy doesn’t fall into these categories, then there’s not too much cause for panic. Different breeds and genetics make for bigger and smaller Guinea pigs.

As long as your pet is eating well, gaining weight, and has a good ‘Heft’ (weight to size ratio) then chances are your pet is happy and healthy. As always if you are concerned about your Guinea pigs weight, then consult your local friendly vet.
How to Weigh your Guinea pig
There’s not a great deal of technical advice on this subject. A decent set of kitchen scales (analog or digital ) and a plastic bowl are sufficient to get the job done.
- Place the plastic bowl on the scales and zero them to ensure an accurate measurement.
- Pop your buddy in the bowl, with something to distract him. perhaps a leafy green to nibble on whilst having his vital statistics taken. Nobody likes to get weighed!
- Once your piggy has settled down, take a measurement.
- Repeat the process 3 times in one day and take the average weight. (add all the numbers up and divide by the number of measurements taken) this ensures small fluctuations caused by eating, drinking and going to the toilet are accounted for.
- Record this in an excel sheet for future reference.
How to tell if my Guinea Pig is overweight
By monitoring your Guinea pigs weight weekly and tracking her weight in a tool such as Excel, it is quite easy to spot if your piggy is creeping too far beyond the average weight.
As mentioned above, not all Guinea pigs will fall into this ‘average weight’ category, so measuring their ‘Heft’ is a good additional method of determining if your pet is on the heavy side.
To measure your Guinea pigs’ Heft, simply check around his ribcage, hips, and spine. You should be able to feel the ribs, hips, and spine. If you can’t, then chances are your Guinea pig is overweight. If the ribs, hips, and spine are obvious and pronounced, then you should read on for what to do if your Guinea pig is underweight.

Excessive Fat around the abdomen and at the top of the legs is also a good identifier. If there is excess fat, your piggy will probably be struggling to move freely and this is a good indication that he might be carrying too much Heft.
You might also see a slow down in activity and an increase in lethargy. Increased sleeping and only managing short trips to the food bowl is
Overweight guinea pigs – risks and complications
Carrying too much weight as for us humans can have a serious impact on health. Some of the more common issues are:
- Additional Strain on the heart, liver, and circulatory system
- Additional pressure on joints and bones
- Diabetes
- Heart disease
- Some Cancers
- Breathing problems
- Lack of mobility and the ability to exercise
- High blood pressure
- Digestive system issues
How can I help My Guinea pig lose weight?
So you have identified that your Guinea pig may be carrying too much Heft, and you would like to tackle the weight issue before it has
Healthy Diet
Guinea Pigs are overeaters, and it is easy to fall into the trap of topping up food bowls and providing extra treats when they run low.

It is important to measure out and regulate exactly how much food they are consuming on a daily basis.
Using your measurements as a benchmark, try cutting back the amount of food you have been providing.
For Example, if you have been measuring out 1 scoop of pellets per day, reduce that to half a scoop. Reduce the fresh veggies to half a scoop from 1 scoop, and same again for fresh fruits. This will ensure the diet is still well balanced but reducing the calorific content in equal measures.
Be sure to have an unlimited supply of grass hay available throughout so your piggy has plenty to keep him busy.
Increase Exercise
Hand in hand with an improved diet, you should also look to increase the amount of daily exercise your
If their living arrangements are on the smaller side, then allow them to have some time out of their home for some exercise. Time out in a Guinea pig run or secure space where they can’t escape or get into any other trouble is ideal. Let them forage around and explore. Perhaps add some toys and games to encourage movement around the space.
Consult your vet
If you are still unsure on what you can do to help your Guinea pig lose weight, then you should take a trip to your local vet for advice. It’s likely they will ask you about food intake and exercise, so be sure to have this information with you and be open and honest about what your Guinea pig gets to eat daily and how much exercise they take.
How to tell if my Guinea pig is underweight
Guinea pigs being underweight is just, if not more serious than having a fat Guinea pig. Therefore it is very important to identify any significant weight loss by tracking the weight of your pet weekly as described above.
To compliment tracking the weight, also apply the Heft measurement to check for prominent ribs, hips, and spine.
If you suspect your pet is underweight and is still losing weight with no change in diet, then consult your vet immediately for further diagnosis.
Guinea pig Heft reference guide
We found this handy guide to physically examining your Guinea pig for Heft to be very useful and informative. With credit to pfma.org.uk: