Body Mass Index is a simple measure of weight relative to height. While not a complete picture of health, it's a useful first step in understanding whether your weight may be affecting your wellbeing.
Enter your height and weight for an instant result. BMI is one indicator of health — your GP can provide a fuller picture.
This calculator is for adults aged 18 and over. For children and young people please use our separate child BMI calculator. BMI is a screening tool, not a diagnostic measure.
Note: These ranges apply to adults. BMI may not be accurate for athletes, pregnant women, or people of certain ethnicities.
Indicative risk levels based on population data. Individual risk depends on many factors — speak to your GP for a personalised assessment.
BMI is a useful starting point, but health is much more than a single number. Here's what else matters alongside your result.