Cat BMI & BCS Calculator

Is your cat at a healthy weight? Calculate body mass index (BMI) and assess body condition score (BCS) — the standard used by veterinarians.

Calculate Your Cat's BMI

Enter Cat Details

ðŸĶīEmaciatedBCS 1-2
📏ThinBCS 3
✅IdealBCS 4-5
⚖ïļOverweightBCS 6-7
ðŸ”īObeseBCS 8-9
⚖ïļ

Enter details to check your cat's BMI

Body Mass Index
UnderweightIdealOverweight
—

Healthy Weight Ranges by Breed

Breed CategoryAverage Healthy Weight RangeIdeal BMI Range
Small breeds (Siamese, Singapura)5–8 lbs25–35
Medium breeds (Domestic Shorthair, Bengal)8–12 lbs25–35
Large breeds (Maine Coon, Ragdoll)12–22 lbs23–33
Giant breeds (Maine Coon male)15–25+ lbs22–32

Frequently Asked Questions

An ideal Body Condition Score is 4-5 on the 9-point scale (or 3 on the 5-point scale). At this score, you can feel ribs easily without pressing hard, there's a visible waist when viewed from above, and a slight abdominal tuck when viewed from the side.

Use two methods: (1) Feel along your cat's ribcage — ribs should be easily felt with light pressure. (2) Look from above — you should see a defined waist behind the ribs. From the side, the belly should tuck upward, not sag down. If you can't feel ribs without firm pressure, your cat may be overweight.

Never put a cat on a crash diet — rapid weight loss can cause hepatic lipidosis (fatty liver disease), which is life-threatening. Aim for 1-2% weight loss per week. Reduce calories by 10-15%, measure portions precisely, eliminate free-feeding, increase play sessions, and consult your vet for a safe plan.

Different cat breeds have very different bone structures and body compositions. A 15-lb Maine Coon might be lean and healthy, while a 15-lb Domestic Shorthair would be significantly overweight. Always consider breed when interpreting BMI results.