Body Mass Index Calculator
Select dog or cat, enter your pet’s details, and receive an instant BMI assessment with personalized wellness recommendations.
Your pet’s BMI assessment
The assessment, the full report and the next steps the calculator suggests.
Your assessment will appear here
Once the details are in, the calculator returns three things:
- a body mass index score and the verdict band it falls in
- a health report built from the frame measurements and the body-condition answers
- the next steps the calculator suggests for that verdict
Result
Health report
Recommendations
Talk. Track. Trust.
Not sure how to interpret the result?
Ask a certified vet about your pet’s weight, body condition and next steps.
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This calculator provides a general estimate and is not a diagnosis. Body shape varies by breed, age, sex, muscle mass and health. Speak to your vet before making major changes to feeding, exercise or weight-management plans.
How the BMI assessment is built
Score your pet on the 9-point body condition chart vets use. Five out of nine is ideal, and each point above is roughly 10 percent overweight.
What the calculator uses
- The breed you pick, matched against the dog and cat breed-size lists to find a size group.
- Current weight and age.
- The frame measurements for that species.
- Activity level.
- Three body-condition observations: rib visibility, waist shape, and abdominal tuck or belly pad.
How the number in the circle is worked out
For a dog the index is weight in kilograms divided by shoulder height in metres multiplied by body length in metres. For a cat it is weight divided by the combined body-length-and-hind-leg frame in metres multiplied by ribcage circumference in metres.
How to judge body condition
Use your hands as well as your eyes. Long or thick coats can hide ribs, waist shape and abdominal fat.
What if my pet’s breed is not on the list?
Pick the closest breed you can. When a size group is not found the report says so, and the rest of the assessment still runs from the measurements and body-condition answers you gave.
Why do the questions change between dog and cat?
The two species are scored from different frame measurements: a dog from shoulder height and body length, a cat from body length, ribcage circumference and hind leg length. Changing the pet on the first screen swaps the whole field set.
Is this the same as a weigh-in at the clinic?
No. It is an estimate built from the numbers and observations you enter, and it is meant to start a conversation rather than replace one.
Ask A Vet also makes a GPS Tracker for dogs and cats. See the GPS Tracker
