This BMI calculator serves people starting a diet, gym and fitness class enrollees, adults interpreting annual health checkup results, patients requiring weight management, and school nurses tracking student wellness. Enter height and weight to instantly compute your Body Mass Index (BMI) as defined by the World Health Organization, then compare two clinical standards side by side: the Korean Society for the Study of Obesity (KSSO) Asian-Pacific thresholds (BMI ≥ 23 overweight, ≥ 25 obese) and the WHO global thresholds (BMI ≥ 25 overweight, ≥ 30 obese). Asians typically accumulate more visceral fat at lower BMI levels, elevating diabetes and cardiovascular risk, which is why Asian standards apply stricter cutoffs. The tool also derives Broca-based standard weight (men: [height(m)]² × 22, women: × 21) and the exact kilograms needed to reach the normal BMI range (18.5–22.9). Important caveat: BMI cannot distinguish between muscle mass and body fat, so bodybuilders and athletes may register as overweight despite low body fat. Complement BMI with body composition analysis (DEXA, InBody) or waist circumference measurement when possible.

• Metric BMI = Weight (kg) / [Height (m)]²
• Imperial BMI = (Weight (lbs) / [Height (in)]²) × 703
• Standard Weight (Men) = [Height (m)]² × 22
• Standard Weight (Women) = [Height (m)]² × 21