Emma Milne
|August 03, 2026
Staying slim is proven to prolong life for both humans and animals, and has lots of health benefits. Many owners wonder, then: “How much should my cat weigh? What is a healthy weight for my cat?” Well, it depends on lots of things, such as age and breed. It’s not so much about exactly how much your cat weighs, as it is about monitoring weight and something we call body condition score (BCS).
Cats don’t tend to vary in size anywhere near as much as dogs, but we do see some differences. You’ll often hear that the ‘average’ cat weighs four kilos, but these days there is a lot of variation. While four kilos would be obese for some cats, it would be underweight for the likes of an adult Maine Coon, for example.
Judging whether your cat is a healthy weight is best done by looking at their body condition score. BCS is scored out of 5 or 9, depending on which scale you use. Our scale is 1-5 where;
5 is obese. A thick layer of fat makes your cat’s ribs very difficult to find. Bonier areas like the knees are covered by a moderate to thin layer of fat.
4 is overweight. The ribs and bonier areas are difficult to feel with a thick layer of fat.
3 is ideal. You can easily feel your cat’s ribs, but there is a slight layer of fat covering them. Bony prominences also have just a slight layer of fat.
2 is underweight. Little fat is covering the ribs, and they are visible without having to touch your pet.
1 is very thin. There is no fat around your cat’s ribs, and they are visible to the eye. Bony prominences are also visible with no sign of fat.
Ask your vet if your cat is an ideal BCS and then you’ll know if their weight is also ideal. Once you get used to judging BCS, you’ll find that you do it subconsciously when you pet your cat. There may not be one ideal weight for cats, but monitoring weight is also important.
Kittens may need several visits in their first year for vaccinations. Adult cats generally benefit from annual check-ups, while senior or special-needs cats might require more frequent visits.
Monitoring weight, as well as BCS, is important throughout life. Weight gain and loss are both possible signs of disease and are sometimes the first thing you’ll notice to alert you to issues.
If you have a kitten, weighing every couple of weeks will tell you and your vet if your kitten is growing properly and at a healthy rate. Monthly weight checks through the rest of your cat’s life will help you spot trends in either direction before it gets out of hand.
Weight gain can easily happen after neutering or as your cat ages, and because it’s usually gradual, it can be difficult to spot if you’re not weighing your cat regularly. It’s much easier to prevent weight gain than lose weight once it’s on, so keeping on top of it and changing rations or food when necessary is the best way forward.
On the other hand, weight loss, as we said, can be an important warning sign of health issues such as kidney and heart disease, cancer or diabetes. Some diseases may be quite advanced by the time your cat is showing clinical signs, so spotting weight loss early on and getting help can, quite literally, be a life-saver.
The bottom line is, there isn’t one correct weight for all cats. Speak to your vet about the right weight and BCS for your cat and then do what you can to keep it that way. Keeping your cat slim will maximise their health and happiness and give you the longest time possible with your beautiful, furry friend.
Reviewed by Dr. Hein Meyer, DVM, PhD, Dipl-ECVIM-CA
Emma Milne, BVSc FRCVS, is a veterinary surgeon and internationally recognized expert in animal welfare and pedigree health. A Fellow of the Royal College of Veterinary Surgeons, she has written nine books, advised multiple animal welfare charities, and regularly speaks on ethics and welfare at conferences worldwide, while serving as a long-standing technical advisor and writer for Hill’s.
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