Free Pet BMI calculator with clear step-by-step results.
Pets have no useful height-based body mass index, so condition is assessed as the percentage above ideal weight, cross-checked against the nine-point body condition score where each point above five represents roughly 10% excess. Safe loss rates are 1% of ideal body weight per week for dogs and 0.5% for cats.
Excess weight
Excess % = (current weight - ideal weight) / ideal weight x 100
Safe loss rate
Weekly target = ideal weight x 1% for dogs, 0.5% for cats
Not a veterinary diagnosis. Weight loss plans for pets should be designed and monitored by a veterinarian, particularly where there is underlying disease or medication involved.
Your vet can estimate it from breed, frame and a hands-on body condition assessment. Breed averages alone are unreliable because frame size varies widely within a breed.
Rapid calorie restriction in cats can trigger hepatic lipidosis, a serious liver condition. Feline weight loss must be gradual and supervised.