Children under 3 years of age should be measured lying down for length. Hospitals have specific measuring boards to measure the length of the child. Remove the child’s shoes, socks, hat, outer clothing and pants and diaper before measuring. The child is placed on his or her back on the centerline of the base of the measuring board with the head touching the headboard and facing upward. The measureer stands on the child’s right side and presses the child’s knees straight with his left hand so that both lower limbs are straight, together and close to the bottom of the measuring board; the right hand moves the footboard so that it is close to the child’s soles and reads the scale of body length. At home, if there is no measuring board, you can also let the child lie on a table or a plank bed and stick a soft ruler on the table or the edge of the bed. Two pieces of cardboard are placed on the top of the child’s head and the bottom of the feet, and the measurement method is the same as that of the hospital’s measuring board, and the length from the inside of the head board to the inside of the foot board is read, which is the child’s body length. When measuring the length, it should be noted that the footboard must be close to the sole of the child’s foot, and not only to the toe, otherwise, the measured length will be greater than the actual length of the child. Children over 3 years old can stand to measure their height. You can use a height meter or nail a ruler to the wall for measurement. The child stands upright, leaning against the post or wall of the height meter, so that the heels of the feet, hips, shoulders and head are in contact with the post or wall, both hands are perpendicular to the sides of the body, both knees stand straight, not bent, the heels are together, the toes are slightly apart, both eyes are looking straight ahead, and the head cannot be tilted up or down. Use a horizontal board to press the top of the head and read the value, that is, the height.