BMI Calculator
Body Mass Index (BMI) is a formula that defines the average relative weight for your height for people over 20 years of age. Although BMI gives you a basic start, it only assesses height and weight; it does not determine muscle mass or take into consideration your lifestyle. BMI is also not a measure of the percentage of body fat.
Body Mass Index (BMI) is a formula that defines the average relative weight for your height for people over 20 years of age. Although BMI gives you a basic start, it only assesses height and weight; it does not determine muscle mass or take into consideration your lifestyle.
Calculate your BMI
BMI is calculated by dividing weight (pounds) by height (inches), squared and multiplying that result by 703 (a conversion factor). Some formulas use 705.
For example: Weight = 170 pounds, height = 72 inches (6’) [170 / (72)2] x 703 = 23
- A person with a BMI between 18.5 and 24.9 is considered to be at a healthy weight;
- with a BMI of 18.5 or less is considered underweight;
- with a BMI between 25 and 29.9 is considered to be overweight.
- A BMI over 30 is considered obese.
- A BMI of 40 or more indicates morbid obesity and can increase risk of death by a high percentage.
BMIs by gender as healthy:
- For men: 23.5 to 25.0*
- For women: 22.0 to 23.5*
While the BMI formula is a good indication of a healthy weight for your height, it is only a general indication. The formula also does not consider your body composition, lifestyle or health condition - being muscular, an athlete, pregnant or younger than 20. The BMI doesn’t differentiate between muscle and fat, so the BMI result for an athlete with lean muscle mass can be misleading. The 23 BMI in the example above indicates that a 6’ person at 170 pounds is healthy; the same 6’ athlete at 230 pounds with a BMI of 31 would be obese. However, most of this person’s weight is probably muscle, which weighs more than fat.
Listed below are links to several Body Mass Index calculators:
- American Heart Association*
- WebMD’s BMI Plus Calculator offers a BMI calculator along with other helpful indicators of your overall health.
These include a BMI calculator for adults and for children and teens.
