BMI (Body Mass Index) is a number calculated from your height and weight. It is used as a screening tool to identify possible weight problems in adults.

What is a healthy BMI?

A BMI between 18.5 and 24.9 is considered normal weight for most adults. Below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is obese.

BMI is a useful screening tool but has limitations. It does not directly measure body fat or account for muscle mass, bone density, age, or sex differences in fat distribution. Consult a healthcare professional for a full health assessment.

BMI Calculator – Body Mass Index Calculator

What is BMI?

Body Mass Index (BMI) is a value derived from your weight and height. It is a simple screening tool that can indicate whether you may be underweight, normal weight, overweight, or obese. BMI is calculated as:

BMI = weight (kg) ÷ height² (m²)

BMI Categories

The World Health Organization defines the following adult BMI categories:

Underweight — BMI below 18.5

May indicate nutritional deficiency or an underlying health condition. Consult a healthcare professional.

Normal weight — BMI 18.5 to 24.9

Associated with the lowest health risk for most adults.

Overweight — BMI 25 to 29.9

Increased risk of developing cardiovascular disease, type 2 diabetes, and other conditions.

Obese — BMI 30 and above

Higher risk of serious health conditions. Class I (30–34.9), Class II (35–39.9), and Class III (40+) indicate increasing severity.

Limitations of BMI

BMI is a screening tool, not a diagnostic measure. It does not directly measure body fat percentage and may misclassify athletes with high muscle mass as overweight, or older adults with low muscle mass as normal weight. It also does not account for fat distribution, bone density, age, or ethnicity. Always consult a healthcare provider for a comprehensive health assessment.