BMI Limitations: What the Number Cannot Tell You

BMI is one part of a health assessment

BMI uses only height and weight. It does not directly describe the balance of muscle, fat or bone, or where body fat is distributed. Similar BMI values can therefore describe different bodies.

Adults and children need different interpretation

This site uses the CDC adult framework for ages 20+. Children and teens require age- and sex-specific interpretation. Do not apply these adult categories to a child.

When this tool is unsuitable

Do not rely on this result during pregnancy, with an eating disorder, or when a condition affects height. High muscle mass and age-related changes can also affect interpretation.

Population differences

The calculator always displays standard CDC adult categories. Some clinical frameworks use lower action thresholds for certain ethnic backgrounds. Local guidance and an individual assessment may therefore differ from this standard category.

A helpful conversation, not a verdict

A qualified health professional can consider symptoms, medical history, examination findings and other measures. No result here is a weight-loss prescription or a judgment about your worth.