Liz Buchanan BVSc MRCVS
Hello! Most cats have reached their adult size by two years old. A 'normal' weight for a fully-grown cat varies from about 2.5 kg to about 5 kgs, but some cats would be underweight at 2.5kg and others would be fat at 5kgs, so it's important to get your vet to examine your particular cat. My first thought on looking at this photo was what neat markings your girl has, but also that it's virtually impossible to assess her size properly from this picture (and nor would I, as we are not her vets). She looks as though she may be reasonably in-proportion but your vet would palpate her muscles and ribs and weigh her. Maintaining a suitable weight now (and we're usually talking avoiding obesity) is an important habit to get into with cats, who can be prone to being overweight in the environments that we tend to keep them in. Furthermore, some cats with underlying illness e.g. those with heart disease etc might not grow to their full potential and this also needs to be identified. Many vets run regular nursing clinics for weight-checks, which can be very helpful in deciding whether or not you should be concerned about your cats' size.