Is my dog too fat? How to check body shape and ideal weight

Print my Pet · 01. October 2026 · 9 min read

Bernese Mountain Dog portrait in Watercolour style, framed above a sofa

The vet's scales show 25 kilos. You nod, because it was about the same last year. But the number only tells you how heavy your dog is. It does not tell you whether he is too fat. A slightly built dog can be clearly too round at 25 kilos, a sturdily built one with the same weight just right.

The answer is in your hands, quite literally. With two hand movements and a look from above, you place your dog on a scale that vet practices use too. From this step you can then work out what he would weigh at an ideal body shape. That is exactly the weight our free food calculator uses once you tell it your dog's body shape.

Why the scales alone decide nothing

Body weight is still the most accurate number you can have about your dog. It just needs a partner: the body shape. Only both together show whether the 25 kilos are muscle and bone or whether there is padding weighing in that does not belong there.

On top of that, overweight creeps up quietly. If you see your dog every day, you barely notice a gradual change. On paper it stands out.

Three hand movements: ribs, waist, belly

You need no prior knowledge for this, just a moment when your dog is standing calmly.

The rib test

Lay both hands flat on his chest and stroke over it with light pressure. At an ideal body shape you cannot see the ribs, but you can feel them well with this light pressure. If there is noticeably more fat over them, you are at step 6. If the ribs are only hard to feel, at step 7.

The view from above

Stand over your dog and look at his back. Behind the ribs there should be an indentation, the waist. If it is hardly recognisable and the back looks broader, that points to overweight. If it is missing completely, it is already clear.

The view from the side

Crouch down and look at the line under the belly. If it rises from the chest towards the back, all is well. If it becomes flatter or the belly even hangs down, your dog is carrying too much.

With long-haired dogs such as Collies, Newfoundlands or Spitz, looking does little. Here only what the hands feel counts. The real shape shows best when the coat lies flat and wet after a bath.

Body condition scoring in dogs in five steps from very thin to severely overweight, each from above and from the side

The body condition scale in nine steps

From ribs, waist and belly line you get a step between 1 and 9. The scale has been tested on many dogs and, with a little practice, also works in the hands of owners. On the right it shows roughly how far the weight deviates from the ideal weight.

Step	How it feels and looks	Deviation from ideal weight
1 and 2: very thin to emaciated	Ribs, spine and pelvic bones clearly visible, no fat over them, strongly tucked-up belly	around 30 to over 40% below
3: thin	Ribs easily visible or felt with hardly any fat over them, pronounced waist	20 to 30% below
4: lean, still ideal	Ribs easily felt with little fat over them, clear waist	10 to 15% below
5: ideal	Ribs not visible but easy to feel, waist recognisable, belly rises	0%
6: slightly overweight	Ribs still felt with somewhat more fat over them, waist and belly line less distinct	10 to 15% above
7: overweight	Ribs hard to feel, hardly any waist, back somewhat broader	20 to 30% above
8: severely overweight	Ribs barely felt, no waist, fat deposits on back and neck	30 to 45% above
9: obese	Ribs not felt, clearly sagging belly, fat also on face, legs and groin	more than 45% above

The target for a healthy adult dog is step 4 to 5. Both belong to the ideal range, and a healthy dog at step 4 does not need to gain weight. Dogs in this range live, on average, healthier and longer than overweight ones.

From scale weight to ideal weight

Here comes the calculation that makes the difference. The food requirement of an overweight dog is never calculated for his current weight, but for his ideal weight. Otherwise you simply feed the overweight along with it.

The formula is short: current weight divided by (1 plus deviation in percent divided by 100). For the deviation you take the middle of the range from the table.

A worked example: A dog weighs 25 kilos and is at step 6. The table gives a deviation of 10 to 15 percent for step 6, the middle is 12.5 percent.

1 + 12.5 ÷ 100 = 1.125
25 ÷ 1.125 = around 22.2 kilos ideal weight

That is exactly what the food calculator does when you enter 25 kilos and step 6 there: it carries on calculating with about 22.2 kilos. At steps 4 and 5 it stays with the weight from the scales, at steps 1 to 3 the plus turns into a minus and the calculation weight is above the current one.

What the 2.8 kilos make in food

The difference sounds small, but goes a long way. For our example dog let us take factor 110 for a moderately active dog. Calculated with 25 kilos, that gives around 1,230 kilocalories a day, with 22.2 kilos around 1,126. With the example dry food from the book at 374 kilocalories per 100 grams, that is 329 grams against 301 grams, almost 30 grams of difference, every day. How the calculation runs in detail from weight to grams is in our article Calculating how much to feed your dog: how much he really needs.

The result remains an estimate. The scale works with ranges, and dogs are built differently. A sturdy dog can weigh a little more at step 5 than the formula says, a delicate one less. So take the ideal weight as a first interim goal and reassess when your dog has got there.

Lose weight slowly, and with a plan

If your dog is at step 6 or above, the obvious thought is: just give a bit less. That often goes wrong. Anyone who gives "a bit less" usually gives too little less, the dog barely loses weight, and after a few months everything is as before. On top of that, protein, minerals and vitamins shrink along with the amount, and he still needs them in full while losing weight.

A real weight loss plan therefore starts at the vet's practice. There they check whether an illness is behind the weight, and you set the target weight and energy amount together. For weight loss, you calculate with the ideal weight and a clearly smaller factor than in everyday life. Which factor fits is decided by the practice.

On pace, the guideline says 1 to 2 percent of body weight per week. Faster is not better, because more muscle can then be lost. For our 25-kilo dog that would be 250 to 500 grams a week. In a large weight loss study, dogs in everyday life lost 0.9 percent per week on average. So it is better to plan on a little more patience.

A few things help in everyday life:

Count everything. For two weeks, write down what really goes into the dog: meals, treats, chews, the piece of sausage for the tablet. If several people feed him, everyone writes it down.
Deduct treats, do not add them. At most a tenth of the daily energy, and that comes off the amount in the bowl. The food calculator therefore asks for treats and chews separately and deducts their energy before the number of grams.
Judge the trend, not the week. Weight fluctuates with faeces, urine and water. What counts is the course over two to four weeks.
Weigh correctly. Same scales, same time of day, ideally in the morning before feeding. You weigh medium and large dogs by first standing on the bathroom scales alone and then with the dog in your arms.

One last point that tends to surprise: exercise helps, but adds up differently than you might think. Three kilometres of brisk walking use around 66 kilocalories in a 20-kilo dog, less than a handful of dry food. Weight is lost at the bowl. And what helps most there is this: weigh the food, do not estimate it. If the bowl is to get a fixed place next to the kitchen scales, you will find a suitable one among our food bowls.

When to go to the vet's practice

The rib test does not replace an examination. In these cases your dog belongs at the practice:

He is at step 6 or higher and is to lose weight. You set the target weight and energy amount together there, and you also agree any later change of amount beforehand.
He is at step 3 or below without you knowing a reason.
He is gaining or losing weight clearly although nothing has changed in food and exercise. An illness such as an underactive thyroid can also play a part in weight.
It concerns a puppy, a pregnant or nursing bitch or a sick dog. They only lose weight under veterinary supervision.

Your next step

Take two minutes today, lay your hands on your dog's chest and look at his back from above. With the step you find and his weight, the food calculator works out the ideal weight and the right daily amount for you. Weigh and feel him every two weeks, and you notice a change long before the scales at the vet reveal it.

The body condition scoring, the ideal weight and a complete weight loss plan for three model dogs are in our book "Hundeernährung und Futterplan" (Dog Nutrition and Feeding Plan), with worksheets for the diary and the weekly check. More on our books page or directly on Amazon.

And when the waist is visible again, it may also go on the wall: as a dog portrait in the style of your choice.

To go with it: the food bowl with your dog's name, made of stainless steel with a motif band.