What is BMI?

BMI, or Body Mass Index, is a number calculated from your height and weight that gives a rough estimate of body fat. It's not a perfect measurement — nothing that simple ever is — but it's widely used as a quick screening tool to flag potential weight-related health concerns in adults. Think of it as a starting point, not a final verdict.

How to Interpret Your BMI Score

The result falls into one of four standard categories:

• Below 18.5 is considered underweight. This can indicate that you're not getting enough nutrition, or in some cases it's a sign of an underlying health issue worth discussing with a doctor.
• 18.5 to 24.9 is the normal range. You're at a healthy weight for your height, which is associated with the lowest risk of weight-related health problems.
• 25.0 to 29.9 is overweight. It doesn't mean something is definitely wrong, but it does mean your weight may be putting added strain on your body and increasing risk factors for things like heart disease and type 2 diabetes.
• 30.0 and above is classified as obese. At this range, the health risks are significantly elevated, and it's worth having a conversation with a healthcare provider.

Important Considerations

BMI has real limitations that are worth knowing about. It can't tell the difference between fat and muscle. A serious athlete might show a high BMI despite having very low body fat. It also doesn't account for age, sex, or ethnicity, which all affect what a healthy body composition actually looks like. Use it as one data point, not the whole picture.

Disclaimer: This tool is for informational purposes only. It is not a substitute for professional medical advice. Always consult with a healthcare provider for any health concerns or before making changes to your diet or exercise routine.