How much should an adult cat weigh? The honest answer is: the weight at which you can feel its ribs easily under a thin layer of fat, see a waist from above, and see a tummy tuck from the side, with muscle held over its spine and hips. That weight is different for every cat, because it depends on breed, frame, and build — a Maine Coon at 6 to 11 kg is a healthy weight at a number that would be obese for a Singapura at 2 to 3 kg. This guide is the adult cat weight calculator in words: the typical weight ranges by size and by breed, how to judge body condition in an adult cat, how weight changes through the adult years, and what to do when an adult cat is overweight or underweight.
Weight is the single most useful number an owner can track in an adult cat, because it is easy to measure, it changes slowly enough to be a trend rather than a daily wobble, and it reflects almost everything else — food, exercise, teeth, and health. An adult cat that is gaining weight is eating more than it burns, and its joints, its blood sugar, and its urinary tract are paying for it. An adult cat that is losing weight without a change in food may be ill, and the weight loss is the clue. Weigh monthly, write the number down, and watch the line, not the single reading. This guide explains how to do that properly, and what the numbers mean.
Adult cat ideal weight by size
The typical adult weight ranges by size are the starting point for an adult cat's target weight: small breeds 2 to 4 kg, medium breeds 3 to 6 kg, and large breeds 5 to 11 kg. Within each range, the right weight for your cat depends on its breed and its frame — a stocky cat at the top of its breed range can be a healthy weight, while a lightly built cat at the same weight can be overweight. The table below gives the size ranges and the typical lifespan for each size, so you can see the weight in the context of the whole of the cat's life.
| Size | Typical adult weight | Typical lifespan |
|---|---|---|
| Small (2–4 kg) | 2–4 kg | 12–16 years |
| Medium (3–6 kg) | 3–6 kg | 12–16 years |
| Large (5–11 kg) | 5–11 kg | 10–14 years |
Breed ranges are a better guide than size ranges where they exist. Small breeds include the Singapura at 2 to 3 kg, the Munchkin at 2 to 4 kg, and the Cornish Rex at 2 to 4 kg. Medium breeds include most domestic and pedigree cats — the British Shorthair at 4 to 8 kg, the Siamese at 3 to 5 kg, and the Bengal at 4 to 7 kg. Large breeds include the Maine Coon at 6 to 11 kg, the Ragdoll at 5 to 9 kg, the Norwegian Forest Cat at 5 to 9 kg, the Turkish Van at 4 to 9 kg, the Siberian at 4 to 9 kg, and the Savannah at 5 to 11 kg. Those ranges are the breed-standard ranges where they are confidently known, and size-class estimates where they are not — the same distinction this site uses on every breed page. Use the breed range first and the size range second, and use body condition to settle the question where the two disagree.
How to judge body condition in an adult cat
Body condition scoring is the method vets use, and it works by feel and by sight, not by the scales alone. Feel the ribs: you should feel them easily under a thin layer of fat without pressing hard — if you have to press to find them, the cat is carrying too much fat, and if they are sharp and prominent with no cover, the cat is too thin. Look from above: there should be a visible waist behind the ribs, narrower than the chest. Look from the side: there should be a tummy tuck, with the belly rising from the chest towards the back legs. Feel the muscles over the spine and hips: a cat that is thin but weak has lost muscle, not just fat, and that matters as much as the number on the scales.
Cats need a slightly different eye from dogs, because their bodies hide weight differently. A long-haired cat can look heavy when it is not, and a short-haired cat can look thin when it is carrying fat under a sleek coat — so feel the ribs and the waist, do not just look at the silhouette. A cat may also carry a small pouch of loose skin on its belly, the primordial pouch, which is normal in many cats and is not the same as fat. The most reliable check is the trend: weigh monthly, write it down, and compare with the cat's own healthy adult weight, not with a breed average. If the trend is up or down by more than about 5% over a few months, ask your vet to look at it. The cat ideal weight calculator gives a starting range from your cat's breed and size.
How weight changes through the adult years
Most adult cats gain weight in the prime and mature years, because activity falls faster than appetite. A cat that played for hours a day at two now sleeps most of the day at seven, but still eats the same amount — and the difference, a few dozen calories a day, adds up to a kilo over a year or two. That is why the first adult change should be food: move from the kitten factor of about 2.5 to the adult factor of about 1.2, weigh monthly, and adjust by 10% at a time. The adult cat food calculator guide gives the calorie tables by weight, and the cat food calculator works them out for your cat's weight and activity.
Neutering is the other big weight change in the adult years: a cat that has been neutered typically needs about 10 to 20% fewer calories than before, and the weight gain that follows neutering is the main risk, not the operation itself. Cut food by roughly 10 to 20% after the operation and watch the waistline for the next few months. In the mature years, from 7 to 10, weight can creep up further, and vet checks should start to include weight, teeth, and blood pressure. From 11, the cat is a senior, and weight needs a different eye — muscle loss matters as much as fat, and the senior cat weight calculator guide explains how to judge it. The adult cat age calculator guide puts the adult years in context, with the human-age equivalents at each age.
What to do if an adult cat is overweight
If your adult cat is overweight, the plan is simple, slow, and steady. Cut food by about 10%, keep treats under 10% of daily calories, and re-weigh in a month. Aim for a loss of about 1 to 2% of body weight per month — faster than that risks muscle loss and, in cats, a serious liver problem called hepatic lipidosis, which can develop when an overweight cat stops eating or eats too little too fast. Never starve a cat, and never put a cat on a crash diet: a cat that stops eating for even a day or two needs a vet visit, not a smaller bowl. Keep play regular and active — a cat that plays hard every day burns more and builds muscle, and play is also how a cat stays confident and engaged.
Ask your vet to set a target weight and a timescale, and to check for the health problems that make weight loss harder — thyroid problems, joint pain that limits movement, and dental pain that changes what the cat will eat. A cat in pain moves less and eats more for comfort, so treating pain is part of treating weight. Do not use a weight-loss food without your vet's agreement, because some weight-loss foods cut protein, and a cat needs protein to hold muscle. The cat food calculator works out daily calories by weight and life stage, and the adult cat food calculator guide gives the calorie tables that make weight control practical. Remember that the goal is not the lowest weight, but the weight at which the cat moves well, plays happily, and holds its muscle.
What to do if an adult cat is underweight
If your adult cat is underweight, do not simply feed more of the same food and hope. First, ask your vet to check for the causes: dental pain that makes eating hurt, kidney or thyroid problems, a food the cat does not digest well, or stress — a cat that is bullied by another cat in the house, or that cannot reach its food in peace, may simply not be eating enough. A vet check, including blood and urine tests when the vet recommends them, is the first step, not the last. Once health causes are ruled out or treated, the feeding plan is to offer more calories in a form the cat will eat: a little more food, split into two or three small meals, warmed slightly to release smell, and with the bowl in a quiet place where the cat can eat undisturbed.
Watch muscle as well as weight: a cat that gains fat but not muscle is not healthier, just heavier. Gentle, regular play helps the cat use extra calories to hold muscle rather than store fat. Weigh weekly while you are working on weight gain, not monthly, so you can see the trend quickly, and write the numbers down. If the cat will not eat, or eats and still loses weight, go back to the vet promptly: a cat that will not eat is always worth a vet visit, and the cause is often treatable when it is caught early. Do not give a cat dog food, cow's milk, or supplements without veterinary advice — cats are obligate carnivores, most cannot digest lactose, and supplements can unbalance a diet that is already complete.
For related reading, see the cat ideal weight calculator, the adult cat food calculator guide, the adult cat age calculator guide, the senior cat weight calculator guide, the kitten cat weight calculator guide, the cat food calculator.
Frequently asked questions
How much should an adult cat weigh?
It depends on breed and frame: small breeds are typically 2 to 4 kg, medium breeds 3 to 6 kg, and large breeds 5 to 11 kg as adults. A Maine Coon is typically 6 to 11 kg, a British Shorthair 4 to 8 kg, and a Singapura 2 to 3 kg. Body condition settles it: you should feel the ribs easily, see a waist from above, and see a tummy tuck from the side.
How do I know if my adult cat is overweight?
Feel the ribs: you should feel them easily under a thin layer of fat without pressing hard. Look from above for a visible waist and from the side for a tummy tuck. If you cannot feel the ribs or there is no waist, the cat is probably overweight — cut food by about 10%, keep treats under 10% of daily calories, and ask your vet to set a target weight.
How fast should an adult cat lose weight?
Aim for about 1 to 2% of body weight per month — faster than that risks muscle loss and, in cats, a serious liver problem if the cat stops eating. Never starve a cat: a cat that stops eating for even a day or two needs a vet visit. Cut food by about 10%, re-weigh in a month, and adjust again if needed.
Why is my adult cat losing weight?
Unexplained weight loss in an adult cat is always worth checking with a vet — it can be caused by dental pain, kidney or thyroid problems, diabetes, or stress, and it is not solved by simply feeding more. Ask your vet to check for the cause first, including blood and urine tests when the vet recommends them.
Should an adult cat weigh less than a junior cat?
A little less is common and usually fine, because activity falls with age. What matters is the trend and the body condition: steady weight with muscle held is healthy, while steady loss — or gain — over a few months is worth a vet check, even if the number still looks reasonable.
How often should I weigh an adult cat?
Monthly for a healthy adult cat, and weekly while you are working on weight gain or loss, so you can see the trend quickly. Weigh at the same time of day, on the same scales, and write the number down — the line over months is what matters, not any single reading.
Results on this page are estimates for general information only and are not veterinary advice. If your pet is ill, underweight, overweight, pregnant, or has a health condition, consult your veterinarian before changing diet or care.