About BMI
The body mass index (BMI) is a simple measure that relates your weight to your height. It is calculated as weight (kg) divided by height (m) squared. It gives a quick estimate of whether your weight is in a healthy range for your height.
Calculators
Body mass index (BMI) calculator
Interpreting BMI
Below 18.5 is considered underweight, 18.5–24.9 normal, 25–29.9 overweight, and 30 or above obese. These ranges are general guidelines for adults.
Criticism of BMI
BMI does not distinguish between muscle and fat mass and does not account for body composition. Athletes with high muscle mass may be classified as overweight despite low body fat.