When you step on a scale, you will see a number that tells you your total body weight. This is fine if you wish to have some general information about your weight, but how do you know if this weight is good or bad? For example, there are two people who weigh 100kg. One is obese and on the way to health problems, the other is an athlete. How do you tell the difference? This is where body composition comes in, seperating Lean Body Mass from total weight. Lean body mass is essentially your fat-free weight. As in the previously mentioned scenario where both people weigh 100kg, the obese person has 35% body fat, meaning only 65kg of his body is fat free weight and 35kgs are fat, where the athlete has 10% body fat, meaning 90kg is fat free weight, and only 10kgs are made of fat!
Now, you are curious about finding out what your body composition looks like. How much body fat do you have? Is your body fat level acceptable? Let's find out!
Please note that the original formula for this calculation is using the American system. I will provide conversion units for the calculation.
Step 1: There are two measurement sites for men (the neck and waist), and three for women (the neck, waist, and hip). All measurements should be taken in centimeters.
- Neck circumference measurement should be taken just above the middle of the neck.
- Waist circumference measurement should be taken close to the belly button, or between the top of the hip bone and the lowest ribs.
- Hip (Women only) circumference measurement should be taken around the widest part of the buttocks.
Step 2: Measure your height in centimeters.
Step 3: Divide the number of each measurement by 2.54
Examples:
Male:
Neck: 43cm ÷ 2.54 = 16.9
Waist: 100cm ÷ 2.54 = 39.4
Height: 180cm ÷ 2.54 = 70.9
Female:
Neck: 29cm ÷ 2.54 = 11.4
Waist: 60cm ÷ 2.54 = 23.6
Hip: 85cm ÷ 2.54 = 33.5
Height: 158cm ÷ 2.54 = 62.2
Step 4: Now that you have the numbers for each measured segment converted, let's proceed to the next step, which is to plug in the numbers to the formula.
Male Formula: Body Fat Percentage (%) = 86.010 x log10 (waist – neck) – 70.041 x log10 (height) + 36.76
Female Formula: Body Fat Percentage (%) = 163.205 x log10 (waist + hip – neck) – 97.684 x log10 (height) – 78.387
Step 5: Calculate the body fat (Example)
Male: 86.010 x log10 (39.4 – 16.9) – 70.041 x log10 (70.9) + 36.76 = 23.44% Body Fat
Female: 163.205 x log10 (23.6 + 33.5 – 11.4) – 97.684 x log10 (62.2) – 78.387 = 17.30% Body Fat
Now that you know how to find your body fat percentage, take a look at the following information to see where that places you on this fitness chart:
Here are the raw number ranges:
Women
Minimal essential fat 10-13%
Athletic 14-20%
Fit 21-24%
Average 25-31%
Obese 32%+
Men
Minimal essential fat 2-5%
Athletic 6-13%
Fit 14-17%
Average 18-24%
Obese 25%+
Please remember, these are tools you can use for reference. The most important thing to remember about fitness is that it has to work for you. Always do what is best for you and your health!