BMI Calculator

What Is Adult BMI?

Body Mass Index or BMI is based on your height and weight. Doctors often use BMI to determine if a person is underweight, at a healthy weight or is overweight. While BMI is accurate for most people, it doesn't work for everyone. It's important to remember that:

  • If you are under 20 years old or pregnant or breast-feeding, the BMI calculator does not apply to you.
  • You could have a high BMI but be at a weight that is considered healthy if you're muscular or athletic.
  • You could have a normal BMI and have poor nutrition.
  • It's important to talk to your doctor about weight-related health risks.


  • Centers for Disease Control and Prevention. Body Mass Index.
    Available at Accessed May 1, 2007.
  • The Practical Guide: Identification, Evaluation and Treatment of Overweight and Obesity in Adults. National Institutes of Health. National Heart Lung and Blood Institute. October 2000.

The BMI calculator is provided for your information only. It is not a substitute for professional medical advice, and may not represent your true individual medical situation. It does not take all possible factors into account in its assessment of your healthy weight. For example, it tends to overestimate body fat in very muscular individuals or in people who are less than 5 feet tall, and may underestimate body fat in people who have lost muscle mass, such as the elderly. Do not use this information to make significant changes in your diet, exercise regimen, or other aspects of your lifestyle without consulting your personal physician or other qualified health care provider as recommended by your physician. Please contact your physician if you have any questions or concerns.