The official reference
The FCI standard states a height at the withers of 32–38 centimetres and a maximum weight of 5 kilograms. Height means floor to withers, not to the top of the head or ears. These describe the breed standard; they do not replace a veterinarian’s assessment of an individual dog.
Why weight is not a garment size
Garments need back length, chest and neck circumference. Weight cannot tell you how long the back is or how the chest is shaped. Two dogs with the same number on a scale may wear different sizes. Measure before ordering, especially for a growing puppy.
Keep the numbers in context
If weight or gait changes unexpectedly, speak with a veterinarian. Do not try to fit a living dog to a table. A breed standard helps explain the breed; clothing has to fit the dog who lives with you today.
Keep a useful record, not a numbers contest
Keep a note with the measurement date, back length, chest circumference and neck circumference. Add the garment model, size and fitting result: for example, “chest comfortable, sleeves too long.” After several purchases, this will be more useful than remembering that you usually bought a small.
Do not compare measurements taken in different positions. Sitting and standing naturally can produce different results. If a new figure is surprising, repeat it calmly, check where the tape starts and avoid tightening it around the chest.
Weight can help you and your vet monitor the dog, but should not become a target simply to match a line in a breed description. Carrier dimensions depend on comfortable accommodation and the operator’s requirements; clothing depends on body shape and cut. One number cannot solve every practical question. Keep separate notes for separate jobs and update them when the dog changes.
Useful? Save it for your next walk.