What is healthy weight range for a cat? Is there any formula like BMI?
I don't know if there are any formulas but I've always thought a healthy domestic cat weighs about 3 to 5 kg depending on the breed. Siamese and Persians tend to be smaller and large cats like Maine Coons can weigh up to 10 kg.
It depends on the breed, age and size of the cat. The best thing to do is take your cat to a vet and have him weighed and looked at.
don't think you need a vet to confirm a cat's weight, it's not very difficult to say if your pet is overweight or not. the graphs above are good