Body fat is only one part of the composition of the human body, and it is particularly important to monitor the fat levels for health and for athletes. There are many ways of estimating the body's fat percentage. The methods described below are calculations based on simple girth or circumference measurements. See the information about %body fat, and also using skinfold measures to calculate %bodyfat (a more common method).
The "Tape Test"
The US Department of Defense measure body composition as part of the fitness assessment of recruits and personnel. Traditionally they have used what is called a 'Tape Test', using body circumference measures to calculate a percent body fat level. This test has always been controversial, and is being phased out.
Formulas from the US Department of Defense
There are formula from the US Department of Defense to compute body-fat percentage using girth measurements and height. There are different formula for males and females. The males require girth measures of the neck and abdominal girth. The females require girths of the neck, waist and hip. You will need a scientific calculator to determine the log calculations.
Using Imperial Units (inches)
This is the formula (Hodgdon and Beckett, 1984) that was taken from the Navy website, and is seen elsewhere on the internet. Note, all measurements are in inches (measured to the nearest 1/4 inch), including height.
- males: % body fat = 86.010 x log10(abdomen - neck) - 70.041 x log10(height) + 36.76
- females: % body fat = 163.205 x log10(waist + hip - neck) - 97.684 x log10(height) - 78.387
Using Metric Measurements (cm)
This is believed to be the metric version of the Navy body fat formula. Note, all measurements are in centimeters to the nearest 0.5 cm, including height.
- males: % body fat = 495/(1.0324-0.19077(log(waist-neck))+0.15456(log(height)))-450
- females: % body fat = 495/(1.29579-0.35004(log(waist+hip-neck))+0.22100(log(height)))-450
This is another formula found online, but there was no mention of the original source. For the females, there are additional measurements needed compared to the formula above.
- males: % body fat = (76.5 * LOG10((abdomen) - (neck))) - (68.7 * LOG10(height)) + 46.9
- females: % body fat = (105.3 * LOG10(weight)) - (0.200 * (wrist)) - (0.533 * (neck)) - (1.574 * (forearm)) + (0.173 * (hip)) - (0.515 * (height)) - 35.6
Other measures of BF% from Girth Measurements
Here are some formula for the estimation of body fat using body circumference measurements (Katch & McArdle, 1983). All circumference measurements are in inches. The values in [square brackets] are used if the individual participates in more than 240 minutes of vigorous activity per week.
- Younger Women (17-26 years): % body fat = (abdominal x 1.34) + (thigh x 2.08) – (forearm x 4.31) – 19.6 [or 22.6]
- Older Women (over 26 years): % body fat = (abdominal x 1.19) + (thigh x 1.24) – (calf x 1.45) – 18.4 [or 21.4]
- Younger Men (17-26 years): % body fat = (upper arm x 3.70) + (abdominal x 1.31) – (forearm x 5.43) – 10.2 [or 14.2]
- Older Men (over 26 years): % body fat = (buttock x 1.05) + (abdominal x 0.90) – (forearm x 3.00) – 15.0 [or 19.0]
- Hodgdon, J.A. and M.B. Beckett (1984) Prediction of percent body fat for U.S. Navy men from body circumferences and height. Report no. 84-11, Naval Health Research Center, San Diego, CA;
- Hodgdon, J.A. and M.B. Beckett (1984) Prediction of percent body fat for U.S. Navy women from body circumferences and height. Report no. 84-29, Naval Health Research Center, San Diego, CA.
- Katch, F.I., McArdle, W.D., Nutrition, Weight Control, and Exercise. Lea & Febiger: Philadelphia. PA, 1983.
- DoD Instruction 1308.3, "Department of Defense (DoD) Physical Fitness and Body Fat Programs Procedures"
- Girth measurement techniques.
- norms for %bodyfat levels for athletes and the general population.
- Other body composition tests using girths are the Waist to Hip Ratio, Waist to Height Ratio
- About body composition tests
- About Anthropometry
- Videos of Anthropometric Tests