BMI, or body mass index, is a widely used measure to assess whether a person's weight is within a healthy range based on their height and weight. The calculation involves dividing an adult's weight in kilograms by the square of their height in meters. For example, a BMI of 25 would be expressed as 25kg/m2.
The BMI ranges differ based on age and gender for children and young people aged 2 to 18. In addition to height and weight, the BMI calculation for this group considers these factors.
Here are the BMI ranges and their corresponding categories:
- Below 18.5: Underweight
- Between 18.5 and 24.9: Healthy weight
- Between 25 and 29.9: Overweight
- 30 or over: Obese
The BMI calculation accounts for natural variations in body shape and provides a range for a healthy weight based on a specific height. However, healthcare professionals may consider other factors in addition to BMI when assessing an individual's weight and overall health.
It's important to note that BMI does have limitations. For instance, individuals with a high level of muscle mass, such as heavyweight boxers, weight trainers, and athletes, may fall into the obese category based on BMI, despite being in good physical shape. Ethnicity can also play a role in health risks, with certain groups having a higher risk of certain conditions like diabetes.
While BMI is a useful tool, healthcare professionals take a comprehensive approach, considering various factors, to assess a person's weight and health accurately. To work out your BMI, check out our BMI calculator