The formula for calculating normal standard weight is weight (kg) ÷ height² (m²), and the resulting value, called the body mass index. If the weight (kg) is divided by the square of the height (m), the value is normal between 18.5 and 23.9. If it is more than 24 and less than 27.9, it is mildly obese, and if it is more than 28, it is obese. If it is less than 18.5, it is lean. This is just a rough calculation. The standard weight of each person is related to gender, race, occupation, age, etc. If you are healthy, it is normal for your weight to be higher or lower than the calculated value. For example, athletes, fitness trainers and people who exercise regularly will have an actual weight that exceeds this standard. Patients are advised to manage their weight according to their body mass index. If their weight is too low, they are advised to enhance their nutrition; if they are overweight or obese, they are advised to pay attention to their diet and strengthen their exercise, and if they have any uncomfortable symptoms, they should go to the hospital in time.