Measuring BMI: What is it, and What Do I Need to Know?

Measuring BMI; Medically Managed Weight-loss

No matter what strategies you use for measuring progress on your journey with weight, it’s important to have an idea of where you’re at along the way. Maybe you use a scale to monitor any changes in weight, or you rely on internal cues that your body projects such as increased energy or greater mobility. Your BMI (or Body-Mass-Index) also provides you with some of those answers, but just what exactly is BMI and what do you need to know about it?

Body-Mass-Index: A Simple Definition

BMI is the most common form of measuring your weight and its connection to your overall health. Your BMI is a number that is calculated using a very simple formula, and it corresponds to a specific chart that places that number into a category. Many health professionals use this information to talk to their patients about their weight and its connection to health.

How Do I Calculate BMI?

An individual’s BMI is calculated by dividing their weight in kilograms by his or her height (squared).

If you want to skip the math and just get your number, there are plenty of online BMI calculators that can do the work for you. The Obesity Action Coalition (OAC) offers a very user-friendly version that can help you determine your BMI.

What Does My Body-Mass-Index Really Mean?

Once you have determined your BMI, you can use this number to identify your corresponding weight category. These categories are as follows:

  • Underweight – BMI <18.5
  • Normal – BMI 18.5 – 24,9
  • Overweight – 25 – 25.9
  • Obesity – 30 – 39.9
  • Severe Obesity – > 40

Although these numbers are helpful, you should also be aware that they are not a definitive representation of your overall health and weight category. Because the number is developed through such a simple formula, it doesn’t take into account factors such as body frame and body composition.

For example: because muscle weighs more than fat, it can alter the accuracy of a BMI reading. Someone who is 6’2″ inches tall weighing 257 pounds would be considered to have obesity, but in reality, they could be in wonderful shape because of their muscular build. So, you might imagine how complicated it can become to classify an individual’s weight category based solely on their BMI. This form of measurement does not take into account what kind of weight you carry and where in your body you typically carry it.

If My BMI isn’t Always Accurate, Why is it Used and What Should I Use Instead?

Although an individual’s BMI isn’t always the best reflection of someone’s health in terms of their weight, it’s a useful tool because we can use this number as a starting point. Your BMI can provide a general indication of your weight category, and it can give you an idea for what kind of goals to set for your overall weight and health.

Some other helpful ways to assess and analyze your weight include:

  • Tracking changes on a scale once a week or even twice a month
  • Paying attention to your body and how you’re feeling physically
  • Observing changes in the way your clothes fit
  • Making regular visits to see your doctor and monitor your health

Want More Information about BMI?

You can learn more about BMI and what you need to know by reading the full article from Your Weight Matters Magazine.