The optimal weight range for a 158cm tall woman is approximately 46.2 to 59.7kg. Under the condition that height is known, weight can be calculated by BMI, which is an indicator for estimating whether a person is thin or obese by weight and height.BMI is calculated by dividing weight by the square of height. BMI is calculated by dividing the weight by the square of the height. There are international and domestic standards for BMI, the former BMI between 18.5~24.9 is normal, greater than or equal to 25 is overweight, greater than or equal to 30 is obese. The latter BMI between 18.5 and 23.9 is normal, greater than or equal to 24 is overweight, greater than or equal to 28 is obese. If the weight calculated by BMI is abnormal, it is recommended to supplement nutrition or reduce weight according to one’s own situation. If wasting or obesity is too heavy, one can go to the hospital for treatment according to the wasting or obesity according to the need.