Calculate body mass index from height and weight. BMI is a screening measure, not a diagnosis or a direct measurement of body fat. The categories in this tool are adult categories and should not be used as child growth percentiles.
How to use this tool
- Select metric or imperial units.
- Enter height and weight and check that both units are correct.
- Read the BMI value together with the limitations rather than treating the category as a health diagnosis.
How to interpret the result
The calculation is weight in kilograms divided by height in metres squared. It does not distinguish muscle from fat or account for pregnancy, growth or individual medical context. Seek qualified guidance for decisions about health or treatment.
Frequently asked questions
Can I use this for a child?
The adult categories are unsuitable for interpreting child or teen BMI. Children require age- and sex-specific assessment using an appropriate growth reference.