BMI (Body Mass Index)

Body Mass IndexBody Mass Index is a simple calculation which uses your height and weight in a standard calculation to determine if your weight is correctly proportional to your height.

The standard calculation follows the format:
BMI = weight in kilograms / (height in metres) x (height in metres)

Am I average?

Probably not! Very few people fit into the category of "Average". The BMI Calculation is, however, worked out for the "Average" person with an "Average" fitness level.

By people who make over average amount of physical training, and therefore have an over average percent of muscle mass, can the BMI calculation result indicate an "Overweight" result when in fact, they are far from being overweight , in such cases it can be more senseful to calculate percentages for "Lean Body Mass" and "Body Fat Percent"

One size fits all!

Many of the popular BMI values are "Standardised" to "Easy to remember" values with rounded up/down values and neutralised gender! For an already generalised value, this "generalising" makes BMI results even a little more averageised!

One of the most popular BMI-Values Tables looks like this:

BMI (Standardised Body Mass Index) One size fits All
under 18,5 Underweight
BMI 18,5 - 24,9 Healthy weight
BMI 25 - 29,9 Slightly overweight
BMI 30 - 39 Overweight
BMI 40 or over Obese

BMI Calculations with FitTrack

FitTrack Healthy Weight and Body Mass Index (BMI) Calculations are based upon the more complex BMI tables from NHANNES II. These tables take the gender into account, because it is normal that men and women of the same height have slightly different threshold values for what is overweight, underweight and healthy weight

Check out the difference for yourself, compare the values of the NHANNES II tables below with the standardised version above

BMI (NHANNES II Body Mass Index) Women Men
Anorexic < 17.5
Underweight < 19.1 < 20.7
Healthy Weight Range 19.1 - 25.8 20.7 - 26.4
Slightly Overweight Range 25.8 - 27.3 26.4 - 27.8
Overweight 27.3 - 32.3 27.8 - 31.1
Obese 32.3 + 31.1 +
Extremely Obese 35 - 40 34 - 39

Trying to calculate a more accurate result

Already a little more accurate by using the "Not So Easy To Remember" tables, FitTrack trys to get a little closer to the truth by taking also the Frame Size and Gender into account.

Find out more about how measure your Frame Size and other Body Measurements ->

Is it good for everyone?

The relation of weight to height - Body Mass Index - is intended only for calculations for the average man/woman in the street. Especially in the case of sporty people and bodybuilders where a greater percent from muscle mass is present together with only small amounts of fat, can a BMI result be deceiving or wrong. This can also be the case for women with a more pear shaped body form.

My BMI Result is Super - then all is ok!?

Not always! Your Percent Body Fat, Lean Body Mass, and Waist to Height Ratio, naturally also play a part.

Even when your BMI value is within the Healthy Range, it can be necessary for a little fine-tuning for excess fat.

Independent from if your BMI result is within the healthy range, it is important to know if you are carrying too much or too little fat around. Excess fat can add extra stress to your body and in severe cases can cause serious illnesses, too little fat can compromise your immune system and normal bodily functions.

FitTrack contains additional calculations - Percent Body fat, Lean Body Mass and Waist to Height Ratio - which can be used to determine if your Body Fat and Lean Body Mass are in healthy balance.