Calves weigh 20 to 40 kilograms, and adult cattle weigh 150 kilograms to 300 kilograms. According to the Global Cattle Breeding Network, the weight of cattle will vary depending on the age of the cattle. An ordinary calf weighs 20 to 40 kilograms, and an adult cattle weighs 150 kilograms to 300 kilograms. Calves of different breeds have different weights at birth, and the weight of an adult cow will vary greatly depending on the breed, gender, feeding conditions, etc.