Understand your starting point.

Calculate adult BMI privately using metric or imperial measurements. Understand standard ranges and why individual clinical assessment matters.

Calculate adult BMI privately

Use metric centimetres and kilograms or imperial feet, inches, stone and pounds. BMI is calculated as weight in kilograms divided by height in metres squared. Measurements remain in your browser tab and are not saved or sent to the clinic.

Standard adult BMI ranges

Below 18.5: underweight range. 18.5 to below 25: healthy weight range. 25 to below 30: overweight range. 30 and above: obesity range. These are standard categories, not personalised health targets.

A guide, not a clinical assessment

For adults aged 18 and over. Do not use during pregnancy, with a suspected or diagnosed eating disorder, or with a condition affecting height. BMI does not distinguish muscle from fat. Some ethnic backgrounds carry greater health risks at lower BMI. This does not diagnose illness or confirm eligibility for treatment.