What is Body mass index (BMI)?

BMI, or body mass index, is your weight in kilograms divided by your height in metres squared. For example, 70 kg at 1.70 m gives 70 divided by 2.89, which is about 24.2. It is a quick screening number used widely by health professionals.

BMI cannot tell fat from muscle, so a muscular person can show a high BMI while being healthy. Some guidelines suggest different cut-offs for Asian populations. Use it as one rough indicator only, along with waist size, fitness and how you feel, and ask a doctor if you want a proper assessment.