How do I tell if my cat is overweight?

Use the Body Condition Score (BCS) 1-9 scale. Feel your cat's ribs — you should feel them with a slight fat cover. Look down from above — there should be a visible waist behind the ribs. About 60% of indoor cats are overweight (BCS 6+).

What is hepatic lipidosis in cats?

Hepatic lipidosis (fatty liver disease) is a serious condition that occurs when a cat loses weight too quickly. The liver becomes overwhelmed with fat metabolism and can fail. Never restrict a cat's calories below 80% of their ideal-weight RER without veterinary supervision.

What is a healthy weight for my cat by breed?

Healthy adult cat weights vary by breed: Siamese (3-5 kg / 7-11 lbs), Persian (3-5.5 kg / 7-12 lbs), Bengal (4-7 kg / 8-15 lbs), Maine Coon (5-11 kg / 11-25 lbs), Ragdoll (5-9 kg / 10-20 lbs), British Shorthair (4-8 kg / 9-17 lbs). The average domestic shorthair/longhair cat weighs 3.5-5 kg (8-11 lbs). However, weight alone is not enough — body condition score (BCS) is a better indicator of health because it accounts for frame size. Two cats of the same breed at the same weight can have very different BCS scores.

How fast should my overweight cat lose weight?

Cats should lose weight very slowly — 0.5-2% of body weight per week is the safe maximum. For a 6 kg cat that should weigh 5 kg, this means losing 30-120 grams per week, taking 2-5 months to reach the target weight. Rapid weight loss (>2% per week) can trigger hepatic lipidosis, a life-threatening condition where fat overwhelms the liver. Our calculator sets a calorie target at 80% of ideal-weight RER, which is the clinical safety floor. Always involve your veterinarian in a weight loss plan, especially for cats that need to lose more than 1 kg.

Should I free feed my cat?

Veterinary nutritionists generally advise against free feeding (leaving food out 24/7) for most cats, especially indoor cats. The primary reason: 60% of indoor cats are overweight or obese, and free feeding is the #1 contributor — cats are natural grazers in the wild (eating 10-20 small prey per day) but domestic kibble is far more calorie-dense than mice. Free feeding also makes it impossible to monitor appetite changes, which are often the first sign of illness in cats — a cat that suddenly stops eating is a medical emergency. Exceptions exist: underweight cats, recovering cats, and some seniors may benefit from free access to food. Best practice is scheduled meals (2-3 times per day) with measured portions based on your cat's MER (use our calorie calculator for the target). Puzzle feeders or food-dispensing toys can simulate the hunting/grazing pattern while preventing overeating. If you must free feed, use a microchip-activated feeder to prevent multi-cat food theft and weigh the food daily to track intake.

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Cat Body Condition Score & Weight Tracker

Assess your cat's body condition visually and get a science-based weight management plan. 60% of indoor cats are overweight — find out where yours stands.

Body Condition Score Assessment

Compare your cat's body shape to the BCS 1-9 images below. Select the image that most closely matches your cat's current physique.

Current weight

Key Knowledge

What Is Body Condition Score (BCS)?

BCS is a 9-point veterinary scale: 1 = emaciated, 5 = ideal, 9 = severely obese. It assesses body fat and muscle, not just weight. BCS is a 9-point scale developed by WSAVA to assess body fat and muscle mass — 1 is emaciated, 5 is ideal, 9 is severely obese. Unlike weight alone, BCS accounts for body frame and breed differences. A healthy cat at BCS 5 has palpable ribs with a light fat cover, a visible waist from above, and a tucked abdomen from the side.

Source: WSAVA Nutritional Assessment Guidelines

Indoor Cat Obesity Epidemic

60% of indoor cats are overweight or obese. Even 1 kg extra increases diabetes risk 4× and shortens lifespan by 1.5-2 years. 60% of indoor cats in the US and Europe are overweight or obese. Even 1 kg (2.2 lb) over ideal weight increases the risk of diabetes mellitus by 4×, shortens lifespan by 1.5-2 years, and predisposes cats to arthritis, urinary tract disease, and hepatic lipidosis. Indoor lifestyle, free-feeding, and lack of enrichment are the primary causes.

Source: AAFP Feline Nutrition Guidelines

Safe Weight Loss for Cats

Cats must lose 0.5-2% body weight per week max. Never restrict below 80% of ideal-weight RER — faster loss risks fatal hepatic lipidosis. Cats must lose weight gradually — 0.5-2% body weight per week maximum. Rapid weight loss (>2%/week) can trigger hepatic lipidosis, a life-threatening liver condition unique to cats. Weight-loss calorie targets should never drop below 80% of ideal-weight RER. The formula: Target kcal = 0.8 × 70 × (ideal weight in kg)^0.75.

Source: AAFP Weight Management Guidelines

How to Feel Your Cat's Ribs at Home

At ideal BCS 5: ribs feel like the back of your hand — palpable with a light fat cover. Hard to feel = overweight; sharply prominent = underweight. Place your thumbs on your cat's spine and fingers on the ribs. At BCS 5 (ideal), you can feel each rib with a light fat cover — like running your fingers over the back of your hand. If ribs are hard to feel (BCS 7+), fat is excessive. If ribs are sharply visible/prominent (BCS 3-), your cat is underweight. Combine with the waist and abdominal tuck visual checks.

Source: WSAVA BCS Assessment Guide

Data verified by petsMetrics using peer-reviewed veterinary sources. Citations: ASPCA, AVMA, AAFP. Last reviewed: 2026.

The Science Behind the Cat BCS & Weight Tracker

The WSAVA 9-point Body Condition Score system is the veterinary standard for objective body fat assessment. Our calculator maps your visual and tactile assessments to the BCS scale. The weight-loss calorie formula is: Target kcal = 0.8 × RER_at_ideal_weight, where RER = 70 × (ideal_weight_kg)^0.75. The 80% floor is a clinical safety limit — dropping below risks hepatic lipidosis. Weight loss rate is capped at 0.5-2% body weight per week. These parameters follow AAFP Feline Nutrition Guidelines and NRC nutrient requirements.

References: AAFP Feline Nutrition Guidelines; NRC Nutrient Requirements of Cats (2006)— via petsMetrics

Check Your Cat's Hydration

Weight management and hydration go together. Use our Hydration Calculator to ensure your cat gets enough water — a critical factor in healthy weight loss.

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