A seven and a half year old boy’s height of 126 centimeters is generally normal and meets the reference standard for children’s height. According to the reference standard for growth and development of children of different ages, the height range that meets the reference standard is between -2SD and +2SD, SD being the concept of standard deviation. If the height of a child in a certain age group is less than -2SD, it suggests short stature, and if the height is more than +2SD, it suggests overstature. The height -2SD and +2SD range between 113.51 and 137.46 centimeters for a 7-year-old boy, and between 118.35 and 143.08 centimeters for an 8-year-old boy, so a height of 126 centimeters for a 7 1/2-year-old boy is within the normal range of heights and is usually normal. It is important to note that children’s height increases at a non-equal rate, and should be evaluated on the basis of the individual child’s own changes, rather than using the so-called “normal values” as a “standard” for evaluation. If there is any obvious abnormality, it is recommended to consult a doctor.