Glossary

Body condition score

A hands-on rating of how lean or fat a cat is, on a scale such as 1 to 9, used by vets because weight alone can mislead.

Also called: BCS, body condition scoring, cat weight chart, muscle condition score

Body condition score, or BCS, is a way of rating a cat's body fat by sight and touch. Vets use a 9-point scale in which 1 is very thin, 9 is severely obese, and 4 or 5 is ideal. A 5-point scale also exists, with 3 as ideal. Both rate the same features.

On a cat in ideal condition, the ribs can be felt under a thin layer of fat, much like feeling the back of your hand. From above, the cat has a visible waist behind the ribs. From the side, the belly tucks up slightly behind the ribs. An underweight cat shows ribs, spine and hip bones easily. An overweight cat has ribs that are hard to feel, a rounded belly and no waist. A loose skin pouch under the belly is normal in many cats.

Weight on the scale cannot tell you whether a cat is lean or fat, because breeds differ in frame, from a small Singapura to a large Maine Coon. The score also tracks change over time. Vets often add a muscle condition score, since older and ill cats can lose muscle even while carrying fat. Ask your vet to show you how to score your cat at each visit, and agree on a target score and weight.

Last reviewed November 7, 2026

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Related terms

Obesity Excess body fat that harms a cat's health, raising the risk of diabetes, arthritis and urinary disease. Diabetes mellitus A disease in which a cat's body cannot make or use insulin properly, so blood sugar stays too high. Wellness exam A routine vet visit for a healthy-looking cat to check its body, update vaccines and parasite control, and catch problems early. Osteoarthritis Wear and inflammation of the joints that is very common in older cats and often shows up as subtle changes in behavior.

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