# What is Body Mass Index?

The BMI formula is a simple combination of your height and weight, which is designed to provide valuable information concerning the health of an individual. The number determines whether or not you are at a healthy weight for your height or if you are overweight, obese or even underweight. There are different formulas that can be used, depending on whether or not you use the metric system for measurements.

The actual BMI formulas are:

BMI= how much you weigh in pounds x 703 ÷ square of how tall you are in inches
Or
BMI= how much you weigh in kilograms ÷ square of how tall you are in meters

Once you have your BMI percentage, you will need to see where you fall on the table. Underweight is considered to be a BMI below 18.5. Normal or healthy weight is 18.5 to 25 BMI. Overweight is 25 to 30. Obese is a BMI of over 30. Because both height and weight are taken into consideration, this is a much more reliable number for determining healthy weight ranges than simply weight alone.

What is the formula for calculating BMI? What does BMI even mean? BMI or the body mass index is an amount of fat that is in the body. If you need to loose weight or rather build up your muscle content and loose body fat, then your BMI will let you know.

Adolphe Quelet who was a statistician from Belgium developed the formula and this was initially known as the Quelet formula. BMI is also known as the body mass indicator and is the international measure for checking you obesity. There are several formulae for estimating your body mass index and all you need is your height and weight. You have to have either a metric measurement of your height and weight to check your BMI which would be in kilo grams and meters or in pounds and inches. Some of these formulas are:

1. BMI = Your weight in kgs. divided by the square of your height in meters
2. BMI = Your weight in pounds multiplied by 703 and divided by the square of your height in inches

To know whether you are in the correct BMI the table is:

Underweight – A BMI less than 18.5
Normal – BMI of 18.5 to 24.9
Overweight – BMI of 25 to 29.9
Obese – BMI of 30 and above

However, it may not be that you have a BMI showing a normal weight and yet be in the normal category. Sometimes even those who have a normal BMI can have extra fat and vice versa. This range of BMI does not apply to nursing mothers or women who are pregnant. See where you stand with our BMI calculator now!

### The History of the BMI Formula

As mentioned above, the BMI formula was originally designed by a statistician from Belgium named Adolphe Quetelet. Early in the 1800s, he created the BMI formula, or the Quetelet scale as it was then known, while doing social research. It was initially meant to measure the body mass index for population groups not individuals. It was used in the study of diet and activity levels for specific social groups.

The term body mass index or BMI began to be used in the early 1970s because of scientist Ancel Keys who was also doing a social study similar to Quetelet’s. However the term caught on and became popular. More and more health care professionals, fitness enthusiasts and individuals began to use the BMI as a guideline for healthy weight determination. It is now a very commonly used tool in the war on obesity.

### How Professionals Use the BMI Formula

Doctors and fitness experts check BMI regularly to make sure that you are at a healthy weight. If you are below an 18.5 BMI, they will advise you to eat more and alter your diet with subtle changes in order to gain weight and be within a normal weight range. If you are in the 25 to 30 BMI range, you are officially overweight. You will be advised to lose weight and exercise more in order to reduce your risk of becoming obese and also to reduce the chance of developing further health problems. They will strictly caution you against further weight gain.

If you have a BMI over 30, doctors will often refer you to dietitians, suggest specific diets and weight loss programs and may even suggest that you talk with a bariatric surgeon to help you lose weight. They typically outline the increased health risks you face, like higher rates of cancer, heart problems, cardiovascular disease, diabetes and much more.

Fitness specialists will often outline a rigid program to improve your health when they discover that you have a BMI over 30. They will give you advice about ways to change your eating habits and how to combine cardiovascular exercise and weight-bearing exercise in order to reap the greatest possible benefits. They may suggest close follow-up to not only monitor your BMI but also to make sure you are taking the right steps and exercising effectively to achieve your goals.

If you happen to be extremely muscled due to an intense weight training program, your BMI may not be an accurate reflection of your health. In addition, if you are pregnant, nursing or have recently given birth your BMI is not a good measure of how much you should weigh for optimal health. Consult with your doctor for more reliable feedback.