How much does a cats brain weigh?
The average cat's brain accounts for 0.9 percent of its total body mass, so because the average cat is around 4kilograms in weight, the brain weighs approximately 30 grams.
Siamese cats pretty much would weigh around as much as your average cat. Depending on the cats personality depends on how much they weigh. For example, a lazy cat is usually more overweight. An energetic cat will burn more fat and weigh less. The more cats eat- or don't eat- all effects their weight, too.