Around four in five owners of an overweight pet describe it as being at a healthy weight. That is not carelessness — body condition is genuinely hard to judge by eye, especially on a pet you see every day. Here is how to check by hand instead.
Body condition score, 1 to 9
Run your hands over your pet and read down the list. Do not look from a distance and do not weigh them and stop there — weight alone says nothing without knowing what the frame is supposed to carry. A score of 4 to 5 is ideal.
| Score | What your hands find | Against ideal weight |
|---|---|---|
| 1. Emaciated | Ribs, spine and hip bones visible from a distance. No body fat at all. | -40% |
| 2. Very thin | Ribs easily seen, spine and hip bones prominent, little muscle mass. | -30% |
| 3. Thin | Ribs easily felt and visible. Obvious waist and abdominal tuck. | -20% |
| 4. Lean | Ribs easily felt under a thin fat cover. Waist clearly visible from above. | -10% |
| 5. Ideal | Ribs felt without pressing, slight fat cover. Visible waist behind the ribs, belly tucks up. | Ideal |
| 6. Slightly over | Ribs need slight pressure to feel. Waist visible but not prominent. No abdominal tuck. | +10% |
| 7. Overweight | Ribs hard to feel under fat. Waist barely visible. Back looks slightly broad from above. | +20% |
| 8. Obese | Ribs felt only with firm pressure. No waist, no abdominal tuck, fat pads over the back. | +30% |
| 9. Severely obese | Ribs cannot be felt under heavy fat. Large fat deposits on the back, tail base and abdomen. | +40% |
Each point above 5 is roughly 10% over ideal body weight. Survey work by the Association for Pet Obesity Prevention has found that around four in five owners of an overweight pet describe their pet as being at a healthy weight — which is why scoring by hand matters more than trusting your eye.
Estimating ideal body weight
If you know the current weight and the body condition score, the ideal weight can be estimated: current weight ÷ (1 + (score − 5) × 0.1). Find your pet’s current weight down the left and their score across the top.
| Current weight | Score 6 | Score 7 | Score 8 | Score 9 |
|---|---|---|---|---|
| 5 kg | 4.5 kg | 4.2 kg | 3.8 kg | 3.6 kg |
| 10 kg | 9.1 kg | 8.3 kg | 7.7 kg | 7.1 kg |
| 15 kg | 13.6 kg | 12.5 kg | 11.5 kg | 10.7 kg |
| 20 kg | 18.2 kg | 16.7 kg | 15.4 kg | 14.3 kg |
| 30 kg | 27.3 kg | 25.0 kg | 23.1 kg | 21.4 kg |
| 40 kg | 36.4 kg | 33.3 kg | 30.8 kg | 28.6 kg |
This is an estimate, and at a score of 9 it starts to overstate the target because the formula assumes fat and lean tissue carry the same proportion of the excess. As your pet loses weight, re-score and recalculate rather than working towards one fixed number.
How fast is safe to lose it
| Pet | Safe loss per week | Why the limit exists |
|---|---|---|
| Dog | 1.0–2.0% of body weight | Faster than this strips muscle along with fat and is usually not sustainable. |
| Cat | 0.5–1.0% of body weight | A cat losing weight faster than this can develop hepatic lipidosis, a liver condition that is often fatal. Cats on a diet must keep eating — a cat that refuses food for more than about 24 hours needs a vet the same day. |
Guidance taken from the AAHA weight management guidelines for dogs and cats. The safe rate assumes the diet is properly balanced — see below.
What not to do
| Common approach | What happens |
|---|---|
| Simply feed half the usual amount | This is the most common mistake and it is harmful. Halving the food halves the protein, vitamins and minerals too, so the pet loses weight while becoming malnourished. Vets use a reduced-calorie diet formulated to stay nutritionally complete with less energy. |
| Cut the food but keep the treats | Treats are usually the missing piece. Work out the treat allowance first — it is often a larger share of the daily total than owners assume. |
| Free-feed and hope | Leaving a bowl down all day makes it impossible to know how much is being eaten, and it is the main reason weight-loss plans fail in cats. |
When to see a vet instead
Ask your vet to set the target weight and the diet, rather than working from a chart. Book an appointment if any of these apply:
- Your pet has gained or lost weight quickly without a change in feeding.
- Your cat has stopped eating, or has eaten much less for more than 24 hours.
- Your pet has diabetes, kidney disease, heart disease, or is on any prescription diet.
- Your pet is pregnant, nursing, or still growing.
- Weight is not shifting after several weeks of a properly measured diet.
This page is general information, not veterinary advice. It has no calculator on purpose: body condition is a judgement, and a target weight should come from someone who can examine your pet.
Why there is no calculator on this page
Every other tool on this site ends in a number you can act on directly. This one deliberately does not. Body condition is a judgement made with your hands, and a target weight is a clinical decision — the safe rate of loss, the right diet and the right timeline all depend on things a web page cannot see. A calculator here would produce a confident-looking number that is worth less than the vet appointment it delayed.
Handle the treats before you change the meals
When owners work out where the extra calories come from, treats are usually the answer — and usually a bigger share than expected. The AAHA guidelines cap treats at under 10% of daily calories, deducted from the daily total rather than added to it. It is worth doing that arithmetic before cutting the main meal, because treats are the easier half of the problem to fix and they alone often close the gap.
What never to do
Do not simply halve the food. That halves the protein, vitamins and minerals along with the calories, so a pet loses weight while becoming malnourished — and it is the mistake most commonly made at home. Weight-loss plans that work use a diet formulated to stay nutritionally complete with less energy. And never treat food refusal as part of a diet: a cat that goes without eating for more than about a day is at risk of liver failure, and that is a same-day vet visit.