Body Mass Index (BMI)

Body mass index, or BMI, is a calculation based on your height and weight to place you in a weight category: underweight, normal weight, overweight, or obese.

BMI can be a useful starting measure to identify your weight classification and risk of comorbidities.

BMI is not relevant if you are under 18 years or pregnant.

BMI is a very general measure that places you in 1 of 6 broad weight categories – underweight, normal weight, overweight, obese.

BMI Calculator

BMI Calculator

Units

Height

Weight

Height

Weight

Your Body Mass Index
Excess Weight

BMI Result

BMI Classes and Comorbidity Risks
  • Classification
  • BMI
  • Risk of Comorbidities
  • Underweight
  • Less than 18
  • Increased
  • Normal weight
  • 18-25
  • Low
  • Overweight
  • 25-30
  • Increased
  • Obese 1
  • 30-35
  • Moderate
  • Obese 11
  • 35-40
  • Severe
  • Obese 111
  • 40 or greater
  • Very severe

Fat predominantly distributed around the waist is also a risk factor for health complications such as cardiovascular disease and type II diabetes. Fat predominantly deposited around the hips and buttocks doesn't have this same risk.