The average weight of a 20 year old depends on height. For 20-year-old men with medium build, who are 6 feet tall, the average weight is 157 to 170 pounds, or about 72 to 77 kilograms.
For women, the average weight is 148 to 160 pounds, or 67 to 72 kilograms. The height-to-weight ratio is an important indicator of good health. Height tends to increase until the age of 18, and weight must increase proportionally. However, most people have problems with obesity. It is important to keep an eye on body weight or body mass index as it allows you to lead a healthy life.