Dog ideal weight calculator: from body condition score

Vets judge weight by body shape as well as the number on the scale. The WSAVA chart scores a dog from 1 to 9: 1–3 under ideal, 4–5 ideal, 6–9 over ideal, and the 2021 AAHA guidelines treat each score above 5 as about 10% overweight. Put the two together and you can estimate the weight your dog would have at an ideal 5.

How to score your dog

Do it with your hands as well as your eyes; a thick coat hides a lot.

1. Ribs. Run your flat hands along the chest. At an ideal score you feel the ribs easily under a thin layer of fat. If you have to press to find them, the score is 6 or more.
2. Waist from above. Stand over your dog. An ideal dog has a visible waist behind the ribs.
3. Tummy from the side. The belly should tuck up towards the back legs.
4. Lower back and tail base. Fat pads here mean a score of 7 or more.

Pick the description in the calculator that fits best. If you're between two scores, do the sum for both; your vet can score your dog at the next visit.

How the estimate is worked out

The 10% per score comes from the 2021 AAHA Nutrition and Weight Management Guidelines, which state that each score above 5 on the 9-point scale is equivalent to being 10% overweight, and that each step up is about 5% more body fat. The WSAVA chart itself gives the descriptions, not the percentages. Example: a 30 kg dog scoring 8 is about 30% over ideal, so 30 ÷ 1.3 ≈ 23 kg.

It is a starting point, not a diagnosis. Very muscular or very old dogs, and dogs at the far end of the scale, are harder to estimate; the AAHA guidelines also recommend scoring muscle condition separately.

From ideal weight to a feeding plan

Feed for the ideal weight, not the current one. Our dog calorie calculator gives the WSAVA daily calorie range for a healthy adult at a given ideal weight; for a dog that needs to lose weight, ask your vet for a plan and regular weigh-ins. Treats count: the WSAVA nutrition checklist flags snacks and table food above 10% of daily calories.

Walks help too, but slowly: see how much exercise a dog needs.

When to see the vet

• Score 1–3. Underweight dogs need a vet check before you change the food: weight loss can come from illness or parasites.
• Score 8–9. The AAHA guidelines list osteoarthritis and endocrine diseases among the problems that come with obesity; your vet can rule out medical causes and set a safe pace.
• Any sudden change in weight or shape, up or down, without a change in food or exercise.

Track the trend

One score is a snapshot. Weighing your dog every couple of weeks shows whether the plan works. In DogsLife, weight tracking is part of DogsLife Plus, next to meals; walks, sleep and potty logging are free.