The average weight of a 12-year-old boy, according to the Centers for Disease Control, is 90 pounds. Boys in the top 10% of weight at this age weigh 120 pounds or more, while those in the bottom 10% weigh 70 pounds or less.
The CDC also provides data on the typical height of boys. The ranges of height for 12-year-olds do not vary as much as the ranges of weight. About 59 inches, or 4 feet, 11 inches, make up the average height.
About 5 feet, 2 inches or taller is the average height for boys in the top 10%. Boys in the bottom 10% of this age group are typically no taller than 4 feet, 7 inches.
