The standard weight for a girl of 1.68 meters is 52 to 67 kg. The standard weight of an individual is usually assessed using the body mass index (BMI), which is calculated by dividing the body weight in kilograms by the square of the height in meters. The normal BMI range is 18.5 to 23.9, while individuals with a BMI greater than or equal to 24 are considered overweight, those with a BMI greater than or equal to 30 are considered obese, and those with a BMI of less than 18.5 are considered to have a low body weight. According to the above calculation method, the weight range of a girl with a height of 1.68 meters should be from 52 to 67 kg. If the weight is less than 52 kg, it suggests that she is underweight and needs to take positive nutritional supplements; if the weight is more than 67 kg, it suggests that she is overweight and needs to control her diet and take proper exercise to reduce her weight.