Is My Cat Overweight?

The body condition score, 1 to 9

Vets score body condition on a nine-point scale rather than weighing a cat against a breed average. A score of 5 is ideal. At 5, the ribs can be felt with light pressure under a thin fat covering, a waist is visible from above, and the belly tucks up slightly from the side.

Scores of 1 to 3 mean a cat is underweight, 4 sits just under ideal, 5 is ideal, 6 and 7 mean overweight, and 8 and 9 mean obese. Each point away from 5 represents roughly 10% away from ideal body weight, so a cat scoring 7 is carrying about 20% more than it should.

The scale works because it assesses body composition directly. Weight on its own cannot tell you whether 5 kg is healthy for the cat in front of you.

How to check your cat at home

You need about five minutes and no equipment. Work through five checks, then compare what you found with the scale.

Feel the ribs. Run both hands along the ribcage. At an ideal score the ribs feel much like the back of your hand: clearly there under a thin layer, but not sharp or bony.

Look from above. Stand over your cat and look straight down. There should be a visible narrowing behind the ribs. A straight or bulging outline means excess fat.

Look from the side. The belly should rise slightly from the chest towards the hind legs. A belly that hangs level, or sags below the ribcage, points to a higher score.

Feel the spine. Vertebrae should be easy to feel through a thin layer of muscle, neither sharply prominent nor buried.

Check the fat pads. Feel over the hips and the base of the tail; a firm layer of fat there pushes the score up. Eyes alone are unreliable: a cat can look normal while carrying 20% excess weight.

Healthy weight ranges, and why breed matters

Most domestic shorthairs sit between 3.5 and 5.5 kg (roughly 8 to 12 lbs) at an ideal score, but frame size moves that range a long way. This calculator uses four reference frames: small, 2.5 to 4.0 kg, for cats such as Siamese and Abyssinians; medium, 3.5 to 5.5 kg, for domestic shorthairs; large, 5.0 to 8.0 kg, for British Shorthairs and Ragdolls; and giant, 6.0 to 11.0 kg, for Maine Coons and Norwegian Forest cats.

Those ranges overlap, which is why a number on the scales settles nothing on its own. A 9 kg cat is comfortably normal for a Maine Coon and far too heavy for a Siamese.

Scoring body condition first, then working back to a target weight, avoids that trap. Enter your cat's current weight and score below, and the calculator estimates the ideal range for that individual cat.

What to do if your cat is overweight

Do not crash-diet a cat. Losing weight too quickly can trigger hepatic lipidosis, a fatty liver condition that can be fatal. Safe loss is no more than 1 to 2% of body weight per week, which for a 6 kg cat is roughly 60 to 120 g.

A workable plan cuts daily calories by 15 to 20%, adds 15 to 20 minutes of active play a day, and slows eating down with puzzle feeders. Weigh weekly on the same scales and judge progress from the trend rather than from any single reading.

Talk to your vet before you start if your cat scores 8 or 9, or if the weight changed without you changing anything: obese cats need supervised weight loss. The stakes are worth the appointment. Cats at 6 or 7 are two to four times more likely to develop diabetes and arthritis, and cats at 8 or 9 average about 2.5 years less life than cats at an ideal score.