What is BMI?

Body Mass Index (BMI) is a person's weight in kilograms divided by the square of their height in metres. It's a rough screening tool for underweight, healthy weight, overweight, and obesity.

Asia Pacific vs WHO — which should I use?

If you're of East, South, or Southeast Asian descent, use the Asia Pacific (WPRO 2000) cut-offs — Healthy 18.5–22.9, Overweight 23–24.9, Obese 25+. Research from the WHO, Singapore MOH, and the APAC cohort studies shows Asian populations face higher cardiometabolic risk (diabetes, hypertension) at lower BMI than European reference populations, so the thresholds shift down by about 2–3 points. The WHO global cut-offs (25 and 30) remain the right choice for most non-Asian populations.

What is a healthy BMI range?

Under the WHO standard, 18.5–24.9 is healthy, 25–29.9 overweight, 30+ obesity. Under Asia Pacific cut-offs, healthy is 18.5–22.9, overweight 23–24.9, obese 25+.

Is BMI accurate for athletes?

BMI does not distinguish between muscle and fat. Very muscular people can have a high BMI while being lean, and older adults can have a normal BMI while carrying excess fat. Use it as a screen, not a diagnosis.

How is BMI calculated?

Metric: weight (kg) ÷ height (m)². Imperial: (weight (lb) ÷ height (in)²) × 703.