Body mass index, or BMI, is a way to help you figure out if you are at a healthy weight for your height. BMI is a number based on your weight and height. In general, the higher the number, the more body fat a person has. BMI is often used as a screening tool to decide if your weight might be putting you at risk for health problems such as heart disease, diabetes, and cancer.
BMI is used to broadly define different weight groups in adults 20 years old or older. The same groups apply to both men and women.
- Underweight: BMI is less than 18.5
- Normal weight: BMI is 18.5 to 24.9
- Overweight: BMI is 25 to 29.9
- Obese: BMI is 30 or more
What is my BMI?
There are several ways to find your BMI.
If a woman who is 5 ft. 4 in. tall is considered overweight (BMI is 25 to 29) if she weighs between 145 and 169 pounds. She is considered obese (BMI is 30 or more) if she weighs 174 pounds or more.
A man who is 5 ft. 10 in. tall is considered overweight (BMI is 25 to 29) if he weighs between 174 and 202 pounds, and is obese (BMI is 30 or more) if he weighs 209 pounds or more.
You can also calculate your own BMI. The actual formula to determine BMI uses metric system measurements: weight in kilograms (kg) divided by height in meters, squared (m2).
When using pounds and inches, the formula needs to be altered slightly. Multiply your weight in pounds by 703. Divide that by your height in inches, squared:
BMI = (your weight in pounds x 703) ÷ (your height in inches x your height in inches)
For example, if you weigh 120 pounds and are 5 ft. 3 in. (63 in.) tall:
BMI = (120 x 703) ÷ (63 x 63) or 84,360 ÷ 3969 = 21.3
This is well within the healthy weight range.