Teenage years are a time of huge structural changes in the body as a result of puberty. As such, weight gain during these formative years is variable, yet normal.
On average, 15-year-old boys have a height of 1.7 metres (67 inches), and 15-year-old girls have a height of 1.63 metres (64 inches). At this age, height usually ranges from 1.55 to 1.85 metres (61 to 73 inches) for boys and 1.5 to 1.75 metres (59 to 69 inches) for girls.
The average weight for 15-year-old boys is 56.2 and 52.6 kg (124 to 116 pounds) for girls. Most boys of this age range from 40.8 to 83.5 kg (90 to 184 pounds) and girls generally weigh from 39 to 81.6 kg (86 to 180 pounds).
A key indicator of whether you are in a healthy weight range is the body mass index (BMI), which measures body fat based on height and weight. Although BMI is unstable in teenagers as a result of varied and rapid growth rates, it can give you an idea of whether you are in a healthy weight range. You can calculate BMI by using online BMI tools or consulting a doctor.