The Centers for Disease Control and Prevention say that the average 12-year-old boy in the United States is 58 inches tall and weighs 90 pounds. The average height and weight of 12-year-old girls in the United States are both 59 inches and 93 pounds.
Rates of growth Between their third birthday and the start of puberty, kids grow about two inches per year, on average. The rate at which boys and girls grow, on the other hand, can be very different. Some kids grow at a pretty steady rate from early childhood to puberty, but most go through growth spurts where their growth rate speeds up for a short time.
Genes and DNA The height and rate of growth of a child depend a lot on their genes. The genes a child gets from their biological parents have a lot to do with how fast they grow. If one or both parents are taller than average, their children are more likely to be taller than average as well.
What Happens to Growth at Puberty Many kids have already started to go through puberty by the time they are 12. During the two to five years that a child is going through puberty, their growth rate usually speeds up a lot, and they can grow up to four inches each year. Girls usually hit puberty a little bit before boys, which is why 12-year-old girls are on average an inch taller than 12-year-old boys. Girls reach puberty on average between 8 and 13 years old, while boys do so between 9 and 15 years old.
Parental Concerns Parents who worry that their child’s growth isn’t normal in some way should have their child’s doctor check on them regularly. A doctor will keep an eye on the child’s height and weight, note any changes, and talk to the parents about the child’s growth. In some cases, a child’s doctor may send the child to a paediatric endocrinologist, a doctor who specialises in growth disorders.
Promoting Healthy Growth Children’s growth rates can also be affected by how they live when they are young. Children will grow up healthy and normally if they get enough sleep, eat healthy meals, and exercise regularly. All children need different amounts of sleep, but the average child needs between 10 and 12 hours a night to be well rested and give their body enough energy to grow normally. A healthy diet and exercise every day, like biking, rollerblading, or sports, can also help kids keep a healthy weight as they grow.