BMI is used to estimate a person’s body fat based on their height and weight. Everyone needs some body fat, but having too much body fat can put a person at risk for health problems such as high blood pressure and diabetes. Having too little body fat is also unhealthy.

How is BMI measured?
BMI is a mathematical calculation of your weight (in Kg) divided by the square of your height (in metres). You can figure out your BMI on your own using this formula: BMI = Weight (in Kg) divided by square of your Height (in metres).
For example, if you weigh 80Kg and are 1.7m (170cm) tall, your BMI = 27.7
In this example, BMI = 80Kg divided by 1.7 x1.7 = 80 divided by2.89 = 27.7

What does my BMI mean?
Your health care provider can tell you if your BMI falls into the underweight, normal weight, overweight or obese category. You can also figure out the outcome yourself using the information below;

BMI: Category:

less than 18.5 Underweight

between 18.5 and 24.9 Normal Weight

between 25 and 29.9 Overweight

greater than or equals 30 Obese


No matter what your BMI is, it’s important to ask if it has changed over the last couple of years. If your BMI changes a lot either up or down, you should talk to your health care provider about possible reasons for the change.

However, you need to note here that BMI is not a tool to determine ideal body weight. It is a tool to help you see whether your weight is increasing your risk for disease

What if my BMI is high?
Talk to your health care provider about whether you should be concerned about your BMI and about healthy ways to manage your weight. Keep in mind that BMI is just an estimate of body fat. Most adult who have a BMI in the overweight or obese category have a high amount of body fat, but there are some who don’t. This is true for muscular adults (especially those who exercise or are very athletic and toned). Their weight may be higher because of extra “muscle mass” and not because of extra body fat.
If your BMI falls in the underweight, overweight, or obese category, you should see your health care provider. He/she can check to see if you are at risk for getting any serious health problems and help you work on a healthy weight management plan, if needed.

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BMI calculator is used to calculate your total body fat. But there are some exceptions to using the BMI calculate, click on the link below to read more.
http://www.gigihealth.com/bmi-calculator-is-my-weight-healthy/