Dog Weight Calculator — Ideal Weight from Body Condition Score
Estimate an adult dog’s target weight from weight and body condition score, with an illustrative weekly loss schedule to discuss with your veterinarian.
Vets judge a dog’s weight with a body condition score (BCS) as well as the scale, because a healthy weight depends on the dog’s frame. On the common 9-point scale, 4–5 is ideal and each point above 5 means roughly 10% extra body weight. This calculator uses that rule to estimate your dog’s ideal weight from its current weight and score, and plans a gradual loss at 1–2% of body weight a week.
How to use this tool
- Weigh your dog and choose pounds or kilograms.
- Pick the body condition score that best matches how your dog looks and feels.
- Choose a weight-loss pace — 1% a week is the gentle option.
- Read the estimated ideal weight, how much to lose and the week-by-week targets, then confirm the plan with your vet.
Formula
Ideal weight ≈ current weight ÷ (1 + 0.10 × (BCS − 5))
Weeks ≈ ln(ideal ÷ current) ÷ ln(1 − weekly rate)
The formula applies above BCS 5; scores 4–5 keep current weight. Underweight dogs need an individually assessed target. BCS 9 can conceal greater excess weight than this approximation. Weekly loss is a share of that week’s weight, so this is an illustrative schedule, not a predicted outcome.
Example
A 30 kg dog scored 7 of 9 is about 20% over its ideal, so its estimated ideal weight is 30 ÷ 1.2 = 25 kg — 5 kg to lose. At 1% a week it loses 0.3 kg in the first week and reaches 25 kg in about 19 weeks; at 2% a week it takes about 10 weeks.
Frequently asked questions
How do I find my dog’s body condition score?
Look from above for a waist behind the ribs, look from the side for a tucked-up belly, and run your hands along the ribs. At an ideal score you can feel the ribs easily under a thin layer of fat.
How fast should an overweight dog lose weight?
AAHA guidance gives a 1–2% weekly goal for dogs, with veterinary monitoring and adjustments for health, age and muscle condition. Confirm the appropriate pace for your dog.
Is this the same as a breed weight chart?
No. Breed ranges describe typical adults, while BCS is about this dog’s own fat cover. A dog can sit inside its breed range and still be overweight, so use both.
Can I use this for a puppy?
Not for planning weight loss. Growing puppies should not be put on a diet without a vet’s advice; use a puppy growth tool instead.
Sources
This tool gives an estimate for general information only. It is not financial, tax, legal or medical advice — check with a qualified professional before you rely on the result.
Last updated: 2026-10-30