BMI Calculator

How to use the BMI Calculator

1. 1
   Choose your units. Pick metric (kilograms and centimetres) or imperial (pounds and inches).
2. 2
   Enter height and weight. Type your current height and weight into the two fields.
3. 3
   Read your result. Your BMI, its category, and the healthy weight range for your height appear immediately.

About Body Mass Index

Body Mass Index was devised in the 1830s by the Belgian statistician Adolphe Quetelet, who was studying the distribution of body types across whole populations rather than assessing individuals. That origin explains both its usefulness and its limits. As a quick, cheap screening measure across large groups it works well, which is why health services still use it. Applied to one person it can mislead badly. BMI takes no account of body composition, so a heavily muscled athlete and a sedentary person of the same height and weight receive identical scores despite very different health profiles. It also ignores fat distribution, and visceral fat around the abdomen carries considerably more risk than the same mass on the hips or thighs. The standard thresholds were derived largely from European-ancestry populations; several health bodies now recommend lower cut-off points for people of South Asian, Chinese and other Asian descent, where metabolic risk rises at a lower BMI. Treat the number here as one signal among several — waist circumference, blood pressure, resting heart rate and blood markers all add information BMI cannot capture on its own.

Frequently asked questions