How Much Should A Guinea Pig Weigh? A Guinea Pig Weight Guide

How to weigh my guinea pig?

Welcome to our complete guide to guinea pig weight! Helping you to answer that important question – how much should a guinea pig weigh?

Guinea pigs’ roundness is integral to their appeal. They’re supposed to be a funny little oval shape, and it’s one of their cutest features.

But when your pet is designed to be rotund, how do you tell when they’re carrying too much weight?

Maintaining a healthy weight is just as important for your guinea pig’s health as it is to yours or mine.

In this article we find out what a healthy guinea pig weight is, what causes guinea pig weight loss, and how to help a fat guinea pig slim down.

So, how much should a guinea pig weigh?

Guinea pig weight

Guinea pig pups weigh around 100g at birth, and reach their adult weight by around eight months old.

Whether you bring your guinea pig home from a breeder as soon as they’re ready to leave mum, or choose them in a pet store when they’re a bit older, it’s a good idea to keep tracking their growth when you bring them home.

In fact, many animal welfare charities recommend weighing your guinea pig every week!

How to weigh my guinea pig?

Why should I care so much about the weight of a guinea pig?

Our domestic guinea pigs’ wild ancestors were prey animals.

For many prey animals, a key strategy for not drawing the attention of predators is not showing when you’re in a weakened state, making you an easy catch.

So, guinea pigs don’t tend to let on when they’re in pain.

This means that when they’re injured or sick, it can take us a while to realize.

To overcome this, there are lots of checks we are accustomed to checking whenever we handle our pigs: we check their eyes, ears, nails, teeth, and the general condition of their coat and skin.

Weighing guinea pigs is another valuable way to increase your chances of spotting health problems early on.

Sure it takes a little more effort, because it involves actual equipment besides our hands and eyes. But a poorly guinea pig may lose weight weight rapidly, so it’s definitely worth it.

Weighing your guinea pig

The easiest way to weigh a guinea pig is on kitchen scales.

Digital or mechanical scales are both fine (but if you’ve never tried digital scales, trust me, you will never look back).

You’ll also need a bowl heavy enough that your pig can’t tip themselves off the scales, but not so heavy that adding the guinea pig tips the scale beyond its range.

Weigh your guinea pig at ground level, so that if they do tip the bowl they can’t also fall from a table or work surface.

If your guinea pig finds being handled or weighed stressful, and they have a bed box which is closed on five sides, try putting whole bed box on the scale, then resetting the scale to zero.

Gently remove the guinea pigs back to their hutch, and their weight will appear as a negative figure on the scales.

Tracking your guinea pig’s average weight

Part of working out the healthy weight for your guinea pig is getting into a routine of checking their weight regularly, so you can tell when it’s gone up or down.

Find whatever routine for weighing your guinea pig works for you.

If you find you keeping forgetting, try setting a reminder on your phone, or get into the habit of weighing them whenever you trim their nails.

What is a healthy guinea pig weight?

Just like people and other animals, guinea pigs come in different shapes and sizes.

Some are naturally more petite, and others are naturally big.

The healthy weight for your guinea pig is the weight that corresponds with a healthy body shape.

And to help you know what that is I have just the thing…

A guinea pig weight chart

To help you judge whether your guinea pig is a healthy weight, the Royal Society for the Prevention of Cruelty to Animals recommends using this Guinea Pig Size-O-Meter.

The Size-O-Meter is a guinea pig weight chart with emphasis on handling your guinea pig and assessing whether their body shape is healthy, rather than dwelling on what the scales say.

It also has clear illustrations so you see what an underweight guinea pig and an overweight guinea pig look like.

How much should my guinea pig weigh?

Provided they have a clean bill of health, they’re eating the right things, and they’ve got the right body shape, then weighing them several times around their first birthday will give you an idea of the right weight for your guinea pig.

Once you have a good idea what that weight is, checking for gains and losses is a helpful insight into the health of your guinea pig.

What is the average weight of a guinea pig?

Hopefully I’ve stressed enough now that there isn’t one magic number which represents the ideal adult guinea pig weight.

But how much should a guinea pig weigh if she is the average guinea pig?

Let’s look at the weight range guinea pigs typically fall into.

Like a lot of animals, male guinea pigs are generally a bit heavier than female guinea pigs, but as you’d expect, there is a bit of overlap too.

On average, male guinea pigs weigh between 910g and 1,360g. That’s 2 – 3lb.

And on average, a female guinea pigs weigh 608 – 1,130g, which is 1.5 – 2.5lb.

Naturally, when weights fall within a range, they tend to cluster in the middle of that range, so in fact the majority of guinea pigs are between 700g and 1,200g, or 1.5 – 2.6lb.

If your guinea pig’s weight falls at the very top or bottom of the expected range, even if they seem healthy, please consider asking a vet to check them over in case they have any underlying health problems.

Weight loss in guinea pigs

So let’s say I’ve convinced you to check your guinea pig’s weight every week.

But you’ve noticed their weight fluctuates every time. One week they’re 950g, the next they’re 970g, and the week after that is seems to plummet to 940g.

When is a guinea pig losing or gaining weight a cause for concern?

Guinea pig losing weight?

Small fluctuations in weight aren’t usually a problem.

If you weigh your guinea pig just after they’ve had a good meal, or been to the toilet, you’re bound to notice a bit of variation.

As a rule of thumb, fluctuations of around 5% aren’t cause for alarm.

But I would be asking myself:

  • Have I weighed them at the same time of day as usual?
  • Have I noticed them eating any less than usual?
  • Are there any other signs they might be unwell?

If I answered yes you either of the second two questions, I’d call my veterinary surgery and ask their advice on whether to come in.

If not, I’d make a mental note to weigh my guinea pig again in a couple of days’ time.

My guinea pig is losing weight

If your guinea pig continues to lose weight over several days, or loses more than 10% of their normal weight, then it’s definitely time to arrange for your vet to see them.

Even brief loss of appetite can have serious consequences for a guinea pig.

We’ll come back to why in minute.

Why is my guinea pig losing weight?

Lots of things can cause your guinea pig to lose weight.


  • Dietary changes
  • Environmental changes
  • Exposure to extreme temperatures
  • Infection
  • Dehydration
  • Liver disease
  • Teeth with a pronounced under-bite or overbite)
  • Undergoing surgery
  • Stress

The best placed person to decide why your guinea pig is losing weight is their vet.

Your vet will ask you lots of questions about your guinea pig’s lifestyle and medical history, as well as performing a thorough physical examination.

Even if you think you can pinpoint the cause of your guinea pig’s weight loss, bear in mind loss of appetite and loss of weight are symptoms of many health problems, so only your vet should make a diagnosis for your pet and decide the best course of treatment.

Is your guinea pig overweight?

Being overweight can be just as dangerous as for your guinea pig as being underweight.

Giving our guinea pigs treats is a fun way to to get a cute reaction out of them, and build a bond. But sometimes it’s easy to overindulge our pets and let them get overweight – and it happens to the best of us.

Unfortunately, a fat guinea pig is not a healthy guinea pig for several reasons.

The risks of being an overweight guinea pig

Carrying too much weight puts strain on guinea pigs’ hearts, liver and joints.

It can also cause diabetes, breathing difficulties, and some cancers.

Being overweight in summer makes it hard to regulate their temperature in hot weather too.

Banishing unhealthy guinea pig fat

The good news is, with some careful changes, you can always help your guinea pig get back to a healthy weight.

*Important note about feeding guinea pigs!*

Never make any sudden changes to your guinea pig’s diet to try and make them lose weight.

Guinea pigs have a suicidal tendency to just stop eating when sudden changes are made to their diet.

However, guinea pigs need their digestive system to be constantly in motion: if their digestive system slows down or stops because they won’t eat (a condition called gastrointestinal stasis), it won’t start again without medical intervention.

So, phase in changes gradually, and don’t eliminate anything they have become accustomed to overnight.

Now back to business…

Always consult your vet before putting your guinea pig on a diet.

They will want to ask you lots of questions about what your guinea pig is currently eating, and it’s natural to feel a bit defensive when we’re told we’ve been getting it wrong. But just concentrate on the changes to be made to move forward.

Many vets advise against feeding muesli these days, because guinea pigs tend to pick out the sugary bits leave important roughage behind. Remember that you need to change from muesli to a high quality pellet, to do so gradually.

They might also recommend swapping store-bought snacks for a wider variety of vegetables.

Unfortunately, the treats sold in pet stores are rarely healthy, so when you want to give your guinea pig a treat, do it by mixing up the fresh component of their diet or throwing in a herb they haven’t tried before.

Exercise also has an important role to play in keeping your guinea pig the right size, so make sure they have plenty of space and opportunity to run around.

Bear in mind they tend towards being crepuscular, which means they’re most active at dawn and dusk. Try to put them in their outdoor run at these times, rather than in the middle of the day when they’ll be more inclined to rest than take advantage of the space.

As your guinea pig slims down, they’ll get healthier, happier, and hopefully even live longer too!

How much does a guinea pig weigh?

So, how much should a guinea pig weigh?

Domestic guinea pigs usually weigh between 700g and 1,200g, with males weighing slightly more than females.

When you bring a new pig home, focus on making sure they are a healthy size using the Guinea Pig Size-O-Meter.

Try and getting into a routine of weighing your guinea pig regularly to find out how much they weigh at their healthy size.

One day having this information might help you recognize when your pig needs urgent veterinary help.

How much does your guinea pig weigh?

Once you’ve put your guinea pig on the scales, tell us what they weighed in at using the comments section below!


  1. My guinea pig has always been quite small body frame. We adopted her two years ago now however she was underweight when we adopted her so I tried everything I could to put some weight on her it worked perfectly however more recently when I’m weighing her it has been a month apart though she’s either lost 40grams or gained 40 grams she’s currently weighing 544 grams & has such a tiny figure she hasn’t grown much since having her to be honest. I don’t know her age she’s going grey around mouth and noise. She doesn’t seem interested in exercise much anymore and her nails kind of curl outwards she gets them cut regularly.
    Wonder what your advice is thank you

  2. Our Dutch girl Terri is 8 months in a couple of weeks today she weighed 1040g and I was shocked. She is super active very sleek looking just solid.

    • That’s ok, a female is fully grown by 8 to 9 months, and the maximum weight by then is about 1300 grams.

  3. My Guinea Pigs range from 550g (two 4 month old sows) to 800g. Going by guideline weights, they the board are underweight and the Sows are low weight but they all have ideal body shape. Maybe they are just bred like that in this area.

  4. my girl Jessie is 1 kg and quite thin but long haired , Lu Lu is 1.1 kg short haired teddy piggy and Lexie is very round and 1.3 ..I worry about her weight but she lives with Matty a well proportioned desexed male who Ihave yet to weigh ..Lexie is always wheeking for food and goes for the options like apple or banana which are high sugar despite the 2 pairs of guineas being fed together in each cage . She is a sweetheart but I do worry as she is very squishy and seems to have no shape , she is also 6 months younger then the other guineas

  5. I have two baby boy guinea pigs they are 8 months old. When I got them, One looked really over weight and the other one looked very skinny. Now 2 months later, The chubby one looks the same size but the skinny one is now much bigger- Is he over eating??

  6. I own two guinea pigs. Sniffles is 1,336 grams. Should I be worried? Toffee is only 981 grams. Does she need to put on weight? Are the cases serious? Please reply with answers soon- I am eager to have happy, healthy pets.

    • she’s very much overweight. And maybe to let her loose weight, you give them a bit of floor time? Don’t let her slouch in a corner, keep her active and playful. Don’t take her on walks, her back bones could break. I hope my advice helped you but it’s 2021 by now so you MIGHT have found a solution. Stay safe Suzy!

  7. I have had guinea pigs all my life, (I’m 55) I live in England & have two Shelties who are called the “Two Fat Ladies”. I think they are called Silkies in the U.S. Now 5 years old they weigh about 2 pounds 5oz each. In the summer their weight drops to just under 2 lbs….
    They live outdoors all year on the lawn, eating grass and hay every day, they have a small wooden shelter in their run (about 10 sq ft)on our lawn filled with hay for warmth in winter and shade in summer., we don’t need a lawnmower.. I give them vegetable peelings from the kitchen (Carrots, cabbage, parsnips, broccoli stalks etc) I occasionally give them fruit such as apple and the odd tomato, they very rarely have a strawberry or a couple of grapes each. They also have some feed pellets and fresh water – they eat a lot of pellets in winter when the temperature drops, they only move into my open porch if it is colder than -5°C (22°F). When I first had guinea pigs as a child we lived in Wales, our family had as many as 20 pigs (inc. pups) at any time, we lived in Wales then and the pigs lived inside an uncovered tractor tyre with hay in the tyre part – we moved it every day so they had fresh grass. & The current residents of that house have an aerial photo of the house taken in the very hot summer of 1976 which shows strange circular patterns in the dry grass of the garden. They were astonished when I told them they were made by guinea pigs not aliens ! Does anybody else keep their pigs outdoors ?

  8. I have 7 piggies. 5 are female and 2 are male. The males have a different cage and the females have one LARGE cage. It’s big and they have their own room. They are, Chocolate, Mazel, Domino, Caramel, Fossil, [boys] Happy and Minipaws. Two of my piggies Domino and Mazel are 4 months old but they are 555 g and 500 g. Are they healthy? If they are underweight, what should I feed them to get them normal? Chocolate is 2 years and so is Caramel. Chocolate is 800 g and Caramel is 798 g. Are they both healthy? Fossil is now 4 years and she is 888 g. Is she healthy? And Happy is now 3 wks. I’m pretty sure he’s healthy and Minipaws is 1 year. I know she’s healthy because my friend said she had a guinea pig the same weight as him and her vet said it was healthy. I am planning to go to the vets next wk or possibly this wk but could anyone reply me quickly? Thnks.

  9. Hey guys! No don’t scroll! Please please please listen to my story! Right, I have a guinea pig called Snowflake. She’s a beautiful white teddy pig and I made her tiny pig-friendly shoes made of a stiff rose red. I didn’t know Snowflake needed a friend (I should have done my research) so I didn’t find out until my sister’s friend visited and said Snowflake needed a partner. I said she doesn’t need one and it was all nonsense but she was acting very strangely so after 4 wks of my stubbornness, I finally decided to get 1. Of course, she wasn’t as dear as Snowflake and I had an icy feeling between us 2. She didn’t adapt well and I wasn’t giving her the right diet and after some days, she died. My sister said I wasn’t taking care of them properly so she took compete care of Snowflake who now lived up to 5 years and is still alive to this day. Currently, she has a partner called Daisy. I sometimes pat Snowflake but she’s scared of me and isn’t tame anymore. I love her dearly still, when she was in my (bad) care she would hop onto my lap and cuddle against my hip and wouldn’t go until I put her in her cage and locked her. I was in the middle of a bad relationship so sometimes Snowflake would be in the cage without any food and would finish the water bottle so there was nothing left. She would bite the cage until she escaped and I hit her and slam her and it’s all my fault. But even through my intensively bad care, she survived and never got scared of me. When I got her 1st ever partner, I didn’t even have time to name her so she’s named Her. I gave Her rhubarb most of the time even though I knew it was bad for them. I was the baddest guinea pig owner everyone can imagine. If there was no rhubarb I wouldn’t go shopping and they wouldn’t have anything except the hay in their cage. Their cage is negatively disgusting because I never clean it because I was selfish and too focused on myself. Snowflake is such a good guinea pig. I knew I couldn’t take care of guinea pigs through my ‘relationship’ that was turning bad but I badly needed someone by my side. After all the drama my sister finally spoke up and she’s taking care of Snowflake and her new partner Miracle. Now I’ve sorted everything out with my relationship and I married to another man who is very kind and is right here on my bed looking at what I’m typing. I love him. Snowflake is next door with my sis, and whenever I want to see her, I go.Snowflake is scared of everyone but fat (in a good way) and healthy. Miracle is healthy too but might not live as long as Snowflake. So anyone who has a similar story like me, you might not have a kind sis like me who would take care of their guinea pigs and I want you guys not to be violent to guinea pigs like I did. Don’t be impatient, please don’t hurt them just because you’ve been hurt. They are innocent creatures, afraid. Not only guinea pigs, I’m saying. Any kind of animal. They just want to be near you. If you can’t take care of them, give them to someone else you know will be a good owner. Please listen to my advice, don’t worry. Be happy.

  10. I recently had a guinea pig called snowflake. I saw a comment by ‘Zara’ and she’s got the same name for a guinea pig! cool! It’s wonderful!

  11. Hi! I’m Colly! I’m 44 and I keep my guinea pigs in a large cage outside. We have no yard or garden so the cage is between our neighbors’ back pipe and our house. One day the guinea pigs were playing in the cage but it swerved around and cracked the back pipe. Our neighbors almost sued us because they are quite grumpy but they give us muffins every month so we said sorry and restored their pipe with our money. they are seniors. That’s when we bought a new house and my neighbors smiled at us and gave us 3 batches of muffins but I could tell they were glad we went. So the new house had about 70 metres of grass and we kept the cage there. There was plenty space and coincidentally, our new neighbors who are younger than me have 3 guinea pigs. I have 2 so I get Hazelnut and Acorn into our neighbor’s house where they keep their boars in a cage. Acorn married the boar so they gave 6 babies who we sold. After that we didn’t get them together. The neighbor Lily and her fiance were great friends with us and they had a rough collie called Madagascar and 4 hamsters and even a horse! Lila, her fiance Toby married later and they said they just couldn’t take care of all the horses after they had their baby 3 years later. So they sold the horse, and gave the guinea pigs to us. The hamsters were sold as well and that left Madagascar who they kept. And so Acorn died and so did a boar of Lily’s until only Hazelnut was left. I partnered her with a sow called Merylyn and Hazelnut died. Merylyn died 2 days later so currently I have 3 guinea pigs again who are totally different. My friendly neighbors have moved to a bigger house for their baby with Madagascar and I’m still living in the same house. Me and Lily don’t keep contact anymore, and I met her last week. I said hi, but she couldn’t remember me at all! It’s so strange how quickly things change!

    • @ilovepiggies!, I have 2 piggies. They live inside. I give them cherry tomatoes 1 a week exactly at Friday. Let me show you my piggie table!

      Monday – Gherkin my piggie gets fed some cos lettuce. My other piggie Gray is a himalayan guinea pig I adopted from a pet store. Gray doesn’t like eating cos lettuce so I give him a small amount of cucumber and some parsley.

      Tuesday – Gray’s favorite! Bell pepper! Gray loves yellow ones so I give him some. Gherkin also gets bell pepper and he doesn’t care about it as long as it’s food! Since Gherkin is a sheltie, many people call him a wuss and a bother. But I ignore them. Sheltie guinea pigs aren’t well liked in my neighborhood.

      Wednesday – Salad mix. A mix of salads and greens. I’ve made a product called hutch mix, a mix of timothy hay, grass hay, a few pellets, oaten hay, barley hay and orchard hay. It’s not imported yet, and not published as it is still being approved in certain factories. But it will be available in 2022.

      Thursday – mint, silver beet and kiwifruit. Of course, it is a high supply of vitamin C and certainly not enough vitamins for them. So I add a supply of rosemary and snow peas [Gray is delighted]

      Friday – A leaf of mint, parsley, kale and carrots. Carrots are a great supply of vitamins for guinea pigs but make sure you only feed carrots to them 1-2 times a week. Kale is great to but should only be fed 3-5 times a week.

      Saturday – half an apple for both of them. Also bell pepper again, a healthy amount of it.

      Sunday – Salad mix. Greens and a mix of salads or lettuce.

      So my guinea pigs eat those! They’re very active and nice. Gray and Gherkin are the best!

      • my shelties are Pry and Gander. They are very strange names but my little sister of 7 named them because Pry always pries when I’m doing my work and Gander nibbles a lot. I live in a farm and I have two ganders that peck a lot so my little sister named her Gander.They both are very tame and eat on my lap. I am 16 and I have a dog walking job so I just want to know if my guinea pigs are healthy. My little sister takes care of the guinea pigs and the other farm animals while I’m away and my mum goes to work as a cleaner at a school and dad works at the farm, selling crops and chicken eggs and meat. I still go to school but I have enough time to care for the piggies. My little sister Abigail feeds them two cups of lettuce and occasionally some carrot. Taking care of piggies is fun but hard as we have to clean their stiff wood cage we built ourselves. The cage itself looks like a weak branch but I will describe it. We used our horse Linda’s barrel for the cage and filled it with hay. We cut a piggie sized hole but slightly bigger in the barrel by a drill and fitted a piggie-sized-but-slightly-larger pipe into the hole. At the end of the pipe, a big cage with glass and fleece liner is there. By big, I mean very big. The cage has a mini pig-friendly slide. If the guinea-pig is scared to go down the slide, there are plenty of things it can hang on to. A small bed is there and balls and bridges for the piggies. There are 4 hideys, one made from logs, one from wood, one from fleece and one from sheer plastic (recycled). There’s plenty of entertainment and a strong 3-inch glass bottle for the guinea pigs. 2 wood sticks lay on a side with a hammock attached to it, and the guinea pig can go there. We have homemade carrot munches as a treat with a special ingredient. So that’s our piggie enclosure!

    • @Ilovepiggies!
      Your story was very touching and I was very enjoyed reading it. So my guinea-pigs, Fanny, Emmy and Avalon.

      Fanny was left abandoned by very vexed and tired people who had life troubles. Their averse manner to us was hurting most of the time. They were unwilling to keep poor Fanny, who, in fact, was the cleanest piggie alive on mother earth! I took care of Fanny for 2 days with plenty of research, and got a new partner for her, Emmy. Fanny was a red tortoiseshell guinea pig with a purplish-black cresent shape on her crest. Emmy was a beautiful piggie, mustard brown and white, with clay beady eyes and a shy manner. Of course, all guinea pigs are shy. It is perfectly normal as well. If you are wondering how I got Avalon and his very unusual name, I was at a fair. A pleading boy was begging me to take the blanket wrapped around him. I took it, and inside a little pouch, were tiny stick-like creatures. ‘Take- Take one!’ he begged. I took one. He got a bit of parsley and fed it lovingly. ‘Don’t have enough money to take care of guinea pigs.’ he said. I shivered. I took one. ‘What’s your name?’ I asked. ‘Um- Avalon. Dunno if you’ll pronounce correctly.’ So Avalon, Emmy and Fanny are with me, forever.

      P.S – My 2 year old piggie Emmy is 770 g. Is she under/overweight? I’m worried about her because she isn’t eating as much and is very quiet and doesn’t wheek a lot. I would really appreciate it if someone replied.

  12. My Guinea pig is over a year old and darling of our house. We named him Whiskey Malhotra and his is as comfy with humans as a pet dog. He is just 1.03kg and I feel he needs to add up 150gms to look cuter. What should I feed him so that he is healthy but adds weight?

  13. I got 3 male piggies. They weigh 1250g, 1400g, 1490g and the weight is staying like that. All three piggies are from the same litter – 1 year, 3 months old.
    They all look healthy and are active. It is hard to believe that they are overweight.
    Anyone experienced that?


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