Obesity and being overweight are conditions that are linked to many other health problems, including high blood pressure, Type 2 diabetes, heart disease, stroke, gallbladder disease, and cancer. Assessing whether one’s weight poses a health risk for diseases and chronic conditions involves measuring key “health numbers”:

  • Body mass index (BMI)
  • Waist size

Body Mass Index (BMI)

Body Mass Index measures your weight in relation to your height. To determine your BMI, measure your height and weight, and then plug them into the BMI formula as follows:

BMI FormulaBMI = (703 x [your weight in pounds]) ÷ ([your height in inches] x [your height in inches])
ExampleA person weighs 150 pounds and is 5’ 5” (65 inches) tall. Calculate BMI as follows:
  • 703 x 150 pounds = 105,450
  • 65 inches x 65 inches = 4,225
  • 105,750 ÷ 4,225 = 25
  • BMI = 24.96

What Your BMI Means

Your BMI score can be interpreted as follows:

Body TypeBMI
UnderweightBelow 18.5
Normal18.5 to 24.9
Overweight25.0 to 29.9
Obese30.0 and above

Waist Size

Your waist size can also be an indicator of how you store fat in your body. To determine your waist size, place a measuring tape snugly around your waist. According to the American Heart Association, men have an increased risk of obesity-related diseases when their waist size exceeds 40 inches; for women, the risk grows when their waist size exceeds 35 inches.

To reduce your waist size, focus on eating regular, balanced meals. Snack on whole fruits, vegetables and low-fat dairy products. In addition, the USDA recommends exercising for at least 30 minutes, at moderate intensity, most days of the week.

Learn More

For more information, visit the Assessing Your Weight and Health Risk web page of the National Institutes for Health.