You’re here because you have concerns over your health and fitness. Good! We all should. More and more people are taking their health and fitness more seriously these days and are looking for tips and tricks to help get started. Your Body Mass Index (BMI) is one of those pieces of information that we all need to know in order to start a great nutrition and fitness program.

Knowing what amount of body fat you have and where your “ideal” range is important to know in order to start planning the permanent changes you will be making to your healthy lifestyle.  BMI is a tool used to measure a person’s weight and height ratio.

It is to be used more as an indicator than a specific hard rule of measurement of a person’s total fat content. A scale is used to determine a persons BMI level.This means that as the BMI score increases, so does a person’s body fat. Yummy (not).

A high BMI may be an indicator of high fat count. Usually the visceral belly fat that is the most stubborn to burn off and keep off. Once you build this fat up, it takes FOREVER to get rid of it. Now with good diet and exercise it can go bye-bye. But without good nutrition and a healthy fitness program, this fat will lead to numerous health issues the longer you allow it to hang around.

Some of those ugly issues that come with poor body health and a high BMI can be:

  • type 2 diabetes
  • stroke
  • heart disease
  • issues with fertility in women
  • high blood pressure
  • osteoarthritis
  • fatty liver disease
  • kidney disease

Its also important to not be in the underweight band either. Having a lack of body fat can cause issues as well like:

  • weakened immune system
  • osteoporosis
  • anaemia
  • issues with fertility in women
  • heart palpitations

As you can see, none of these are fun the older you get, and they are easily fixable IF YOU maintain a good health and fitness program. BMI can and should be used as a screening tool only but not a diagnostic of the total body fat or health of a person. Always consult your doctor.

How to calculate Body Mass Index

The Body Mass Index is a calculation using height and weight. The BMI formula is = kg/m2 where kg is a person’s weight and m2 is their height in metres squared. A score of 25.0 or more is considered “overweight”. If you fall in the range is 18.5 to 24.9, you’re doing great. Depending on your metabolism and current lifestyle, BMI applies to most people ages 18-65.

Who shouldn’t use a BMI calculator

BMI is not used for muscle builders, extremely fit athletes, pregnant women, the elderly or young children. That is because BMI only looks at the total number, not the lifestyle where fat or muscle make up a persons weight. Athletes, may have a high BMI due to muscles mass but not be at greater health risk to obesity. Children and the elderly should be excluded due to them not finishing growing or due to other health related issues for seniors.

Always consult your doctor. Duh.

Now the fun part, the ranges of BMI calculator. This should be used as a general indicator of body fat. It should give you an idea of where you are on this scale, and can and should be used to further discussions with your health practitioner.

Your BMI will fit into 5 scores:

  • under 18.5 – This is described as underweight
  • between 18.5 and 24.9 – This is considered as healthy
  • between 25 and 29.9 – This is described as overweight
  • between 30 and 39.9 – This is considered obese
  • 40 or over – This is considered severe obesity



Here is a reference chart to help you gauge your BMI level.

Image courtesy of wikipedia


1. World Health Organization. Obesity and overweight. Fact sheet Number 311. September 2006. Accessed January 25, 2012.

Hopefully this helps you arm yourself with more knowledge around your health. Remember to this knowledge for good and not evil 🙂

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