1. The standard height for an 18-year-old girl is approximately 160.6 centimeters, with a standard weight of around 51.41 kilograms.2. The ideal height-to-weight ratio is a critical indicator of a person's health status. Being underweight or overweight can signal health concerns, highlighting the importance of accurate height and weight data.3. There are various methods to calculate height and weight standards, with the World Health Organization (WHO) providing one such method that is applicable to both men and women.4. According to the WHO calculation, the formula for男性的 standard weight is: (Height cm - 80) × 70% = Standard Weight, and for女性的 standard weight is: (Height cm - 70) × 60% = Standard Weight.5. The calculation for being overweight is given by the formula: Overweight Percentage = [(Actual Weight - Ideal Weight) / Ideal Weight] × 100%. The normal weight range is plus or minus 10% of the standard weight, with mild obesity ranging from plus or minus 10% to 20%, moderate obesity from plus or minus 20% to 30%, and severe obesity being over plus or minus 30%.6. Another method is the Standard Skinfold Thickness Weight Method, which categorizes obesity into mild, moderate, and severe levels.7. The Body Mass Index (BMI) method is another commonly used approach to assess weight, with the formula: BMI = Weight (kg) / (Height (m) × Height (m)).8. For different populations in China, specific ideal weight formulas exist. The ideal weight calculation for northern populations is: [Height (cm) - 150] × 0.6 + 50, while for southern populations, it is: [Height (cm) - 150] × 0.6 + 48.