What is the mass of a 12-year old?

The mass of a 12-year-old can vary significantly based on factors like genetics, diet, and physical activity. On average, a 12-year-old boy typically weighs between 70-100 pounds (32-45 kg), while a 12-year-old girl usually weighs between 65-95 pounds (29-43 kg). However, individual weights can differ widely, so these figures are just general guidelines. It's important to consider that growth patterns vary among children.