How to calculate BMI

The BMI calculator is a useful tool that measures if you are overweight, underweight or just right. His weight alone is not enough to say since a tall, thin man can easily weigh more than a low but flimsy woman. The body mass index, or BMI, overcomes this problem by finding a relationship between its weight and height and returning a single number. This number will be adjusted to a category on the scale of the BMI ranges, which are defined as underweight, normal, overweight and obese.

To calculate your BMI on your own, and what the number means for you, you should know:

• How to calculate BMI.

• What is a normal BMI?

• What are the different IMC ranges?   

How To Calculate BMI

First, let's cover the calculation:

1. Divide your weight (in kilograms) by your height (in meters).
2. Divide the answer according to your height again to get your BMI.

So the formula for the body mass index is the following:

BMI = weight / height².



Normal BMI

Our BMI calculator makes it a piece of cake for you to find your number. However, remember that the BMI is a rough estimate. The result can be somewhat deceptive for people who are well-muscled (like bodybuilders) or for those who have lost a significant amount of muscle (such as the elderly).


If you are not sure whether or not you are in the "normal" range of muscle mass, consider using one of our more specialized calculators. The body fat calculator can concentrate on your body fat percentage, while our lean body mass calculator can tell you how much you would weigh without fat.



BMI ranges


There are five basic ranges within the IMC scale:

• Low weight = less than 18.5

• Normal weight = 18.5 - 24.9

• Overweight = 25 - 29.9

• Obesity = 30 - 35

• Severe obesity = 35 and more

The BMI Prime is an ingenious modification of our own BMI calculator. It is a decimal number where 1.0 = the upper limit to the "normal BMI" range. It is a very easy way to see if you are overweight or not. If your BMI Prime is more than 1, then you have some weight to lose.