BMI Calculator
Calculate body mass index in metric or imperial units, with a healthy weight range.
BMI is a rough screening number for adults. It does not measure body fat and can mislead for athletes, older adults and children. Talk to a doctor for health advice.
About this tool
Body mass index compares weight to height as a quick screening number for adults. Enter your height and weight in metric or imperial units to see your BMI, the standard category, and the weight range that falls within the 'healthy' band for your height. This is a general guide, not medical advice.
How to use it
- Choose metric or imperial units.
- Enter your height and weight.
- Read your BMI, category and healthy weight range.
Frequently asked questions
What are the BMI categories?
Under 18.5 is underweight, 18.5 to 24.9 is a healthy weight, 25 to 29.9 is overweight and 30 or more is obesity (World Health Organization adult ranges).
Is BMI accurate?
It is only a screening tool. It ignores muscle mass, age and body shape, so athletes and older adults can get misleading results.
Is this suitable for children?
No. Children and teens are assessed with age- and sex-specific growth charts.