What Is BMI?
The BMI (Body Mass Index) is used by the medical profession to quickly and simply determine a person’s weight in regard to their height.
From a straight forward calculation the BMI factor can be gained and gives a measure which can be used to determine if a person is underweight, of normal weight, overweight or obese.
Use our calculator below to discover your BMI.
Using Your BMI Number
Once you have your BMI number look at the table below to
determine if you are underweight, normal, overweight or obese
BMI ranges
For most adults, an ideal BMI is in the 18.5 to 24.9 range.
For children and young people aged 2 to 18, the BMI calculation takes into account age and gender as well as height and weight.
If your BMI is:
- below 18.5 – you’re in the underweight range
- between 18.5 and 24.9 – you’re in the healthy weight range
- between 25 and 29.9 – you’re in the overweight range
- between 30 and 39.9 – you’re in the obese range
BMI takes into account natural variations in body shape, giving a healthy weight range for a particular height.
As well as measuring your BMI, healthcare professionals may take other factors into account when assessing if you’re a healthy weight.
Muscle is much denser than fat, so very muscular people, such as heavyweight boxers, weight trainers and athletes, may be a healthy weight even though their BMI is classed as obese.
You should not use BMI as a measure if you’re pregnant. Get advice from your midwife or GP if you’re concerned about your weight.