Variable Key
Metric formula
Weight in kg, height in metres.
Imperial formula
Weight in pounds, height in inches.
BMI categories (WHO)
Standard weight status categories.
Ideal weight from BMI
Target weight to reach a BMI of 22 (mid-normal).
Body Mass Index (BMI) is a screening number calculated from your weight and height. It provides a quick indicator of whether someone may be underweight, normal weight, overweight, or obese. BMI is a population-level tool — it does not diagnose individual health.
Pro Tip
Waist-to-height ratio (waist ÷ height < 0.5) is considered by many researchers to be a better single-number health predictor than BMI.
Did You Know?
BMI was invented by Belgian mathematician Adolphe Quetelet in the 1830s as a statistical tool for studying populations — he never intended it to be used to assess individual health.
References