BMI Calculator

Body mass index (BMI) is a measure of body fat based on height and weight that applies to adult men and women. This calculator provides BMI and the corresponding BMI weight status category for adults, 20 years old and older.

A Healthy Weight

Reaching and maintaining a healthy weight is important for overall health and can help you prevent and control many diseases and conditions. If you are overweight or obese, you are at higher risk of developing serious health problems, including heart disease, high blood pressure, type 2 diabetes, gallstones, breathing problems, and certain cancers. That is why maintaining a healthy weight is so important: It helps you lower your risk for developing these problems, helps you feel good about yourself, and gives you more energy to enjoy life. 

Overweight and Obesity

Overweight is having extra body weight from muscle, bone, fat, and/or water. Obesity is having a high amount of extra body fat. Body mass index (BMI) is a useful measure of overweight and obesity. The information on this Web site will provide you with information about BMI (including limitations of this measure) and how to reach and stay at a healthy weight. Talk to your health care provider if you are concerned about your BMI.

Factors that Contribute to a Healthy Weight

Many factors can contribute to a person’s weight. These factors include environment, family history and genetics, metabolism (the way your body changes food and oxygen into energy), and behavior or habits.

Energy Balance

Energy balance is important for maintaining a healthy weight. The amount of energy or calories you get from food and drinks (energy IN) is balanced with the energy your body uses for things like breathing, digesting, and being physically active (energy OUT):

  • The same amount of energy IN and energy OUT over time = weight stays the same (energy balance)
  • More energy IN than OUT over time = weight gain
  • More energy OUT than IN over time = weight loss

To maintain a healthy weight, your energy IN and OUT don’t have to balance exactly every day. It’s the balance over time that helps you maintain a healthy weight. You can reach and maintain a healthy weight if you:

  • Follow a healthy diet, and if you are overweight or obese, reduce your daily intake by 500 calories for weight loss
  • Are physically active
  • Limit the time you spend being physically inactive

(From: National Heart, Lung and Blood Institute)