BMI categories for adults
- Below 18.5: underweight
- 18.5–24.9: healthy weight
- 25–29.9: overweight
- 30 and above: obesity
BMI = weight (kg) ÷ height (m)². It is a quick screening measure, not a diagnosis: it does not distinguish muscle from fat, and it is interpreted differently for children, athletes, older adults and some ethnic groups.
Frequently asked questions
Is BMI accurate?
BMI is a useful population-level screening tool, but it does not measure body fat directly. Very muscular people can have a high BMI while being healthy. Talk to a doctor for a personal assessment.
Does this work for children?
No. Children and teens need age- and sex-specific BMI percentiles. Use this calculator for adults (20+).
Is this medical advice?
No. This calculator is for general information only.