How it works
- BMI = weight (kg) ÷ height (m)².
- Categories (adults): under 18.5 underweight, 18.5–24.9 normal, 25–29.9 overweight, 30+ obese.
- BMI does not distinguish muscle from fat, so athletes and older adults may be misclassified.
Frequently asked questions
Is BMI accurate?
BMI is a quick screening tool, not a diagnosis. It does not account for muscle mass, bone density or fat distribution.
Can children use this calculator?
No. Children and teens need age- and sex-specific BMI percentiles. Ask a pediatrician.
Results are estimates for general information and are not financial, medical or professional advice.