Body Mass Index (BMI)
Body Mass Index (BMI) is a quick and easy way to determine your stored body fat. BMI is a number calculated by using two measurements: weight and height. The number is used to identify your risk for health related diseases based on excess weight.
Because BMI only uses two measurements, it is a cheap and easy-to-use method for physicians and the general public. BMI is also a method used frequently to assess a whole population for obesity.
Although BMI is an indirect method of measuring body fat, it is popular among clinicians. The direct, alternative methods to measure body fatness and obesity are:
- Skin fold thickness measurements
- Underwater weighing
- Bio-electrical impedance
- Dual-energy X-ray absorptiometry (DXA)
- Isotope dilution
To calculate your BMI (using pounds and inches), divide your weight by your height squared and multiply by a conversion factor as shown below:
For example, if you weigh 150 pounds and you are 5 foot 7 inches tall (1 foot =12 inches), you would have a BMI of:
150/ ^2 x 703= 150/ 4,489 x 703= 0.0334 x 703= 23.4
The table below explains what your results would mean in terms of weight status. Looking back at the example above, 23.4 falls in the healthy weight range.
|18.5 – 24.9||Normal|
|25.0 – 29.9||Overweight|
|30.0 and Above||Obese|
You can also use a BMI calculator.
A high BMI correlates with an increased risk of certain diseases such as:
- High blood pressure
- Heart disease
- High cholesterol
- Type 2 Diabetes
- Female infertility
If you have a high BMI, losing as little as 10 percent of your current weight will help improve your health. To lose weight, burn more calories than you consume by eating less and exercising more. To get more information on how much you should be eating, check out the How Much Should I Eat? article.
Look at tips on healthy eating and exercise here:
Back to top
Public Health Education Intern
Reviewed By: Nancy Brown, Ph.D.
Last Reviewed: August 2013
Below are links PAMF accessed when researching this topic. PAMF does not sponsor or endorse any of these sites, nor does PAMF guarantee the accuracy of the information contained on them.
About BMI for Adults, Centers for Disease Control (CDC).
BMI calculator, Centers for Disease Control (CDC).
For More Information:
See our articles on Body Image.