The standard height of a 4.5 week old boy is 107.7cm and the corresponding standard weight is 17.75kg. If the height of a 4.5 week old boy is between 104.9 and 110.5cm, it is considered to be within the upper and lower standard deviation and is approximately normal. If the height of a 4.5 week old boy is below 100cm, he is considered short. If you want to measure the specific standard of a child’s height, you need to do a bone age test for your child. You can go to the hospital for a bone age test to clarify whether your child’s actual height is within the normal range. At the same time, in daily life, we should achieve a balanced and reasonable diet, avoid picky eating and partial eating, to do appropriate to enhance the bouncing type of physical activity, which is conducive to the growth of children, and to ensure sufficient sleep every day, which is conducive to the growth and development of children.