What is the Skinfold Test?
A Skin Fold Test is a method of estimating body-fat percentage by taking skin-fold caliper measurements in 3-9 different locations on the body (see glossary for pictures), and then applying the results into one of the various formulas available.
To get the best and most consistent measurements, all skin-fold measurements should be taken on the same side (usually on the right side) and by the same person.
Also, a minimum of two measurements should be taken at each location. If the two measurements differ by more than 2 millimeters, a third measurement should be taken. The body composition calculator then uses the average of the 2-3 measurements when making the calculations.
7-Site Skinfold Measurement Sites
Here are the seven skin fold measurement sites for both men and women:
|The pinch is taken between the nipple and the armpit (axilla) but closer to the armpit, approximately 1/3 the distance. The skin fold is a diagonal one in the direction of nipple-armpit line.|
|A vertical or horizontal fold is taken 2 centimeters to the right of the bellybutton (umbilicus). The vertical pinch is mostly used as the fat folds easier with most people. Some might find the horizontal pinch to fold easier. Use the direction that allows the most comfortable measurement.|
|The skin fold here should be taken in the front, halfway from the upper part of the knee (proximal patella, where it corners when the leg is bend) and the fold above the thigh when the leg is raised (inguinal fold). The vertical fold should be pinched a little harder as fat and skin tissue in this area tends to be somewhat firmer. The thigh skin fold may therefore overestimate fat content.|
|Tricep (upper arm, back)|
|Pinch a vertical skin fold halfway the upper arm. If you want to be more precise, use a tape between the bony top of the shoulder or acromiale (do not confuse it with the bony upper part of the shoulder blade!) and the most prominent tip of the elbow (radiale). Mark a dot or a horizontal line at half the measured distance, that is where the vertical fat fold should be pinched. Face the hand palm forward.|
|Subscapula (shoulder blade, lower tip)|
|Locate the bottom tip of the shoulder blade (scapula) by moving the arm behind the back. Move the arm back to its original position. Take the skin fold at approximately 2 centimeters below the bottom tip at an angle of 45 degrees, almost parallel to the inside angle of the shoulder blade.|
|Hip (suprailiac or iliac crest)|
|This skin fold is right below the front or anterior part of the armpit (axilla). From here follow a vertical line until you hit the hipbone. The skin fold is an angled one (approx. 45 degrees going up and away from the body) 2 centimeters right above the iliac crest. The fold spot should be between the top of the hipbone on the side and the bony part on the lower right of the belly, which is still the same hipbone.at an angle of 45 degrees, almost parallel to the inside angle of the shoulder blade.|
|Midaxillary (armpit at fifth rib)|
|This fold is taken on the side of the torso, horizontally or vertically at the fifth rib. The most common however is a vertical fold. Its position can be determined by locating the lower tip of the breast bone (xiphoid process) and following a horizontal line to the side of the torso until you are right below the arm pit (axilla). The arm should be raised at approximately chest height.|
7-Site Skin Fold Test Calculation
The formulas used for calculating the male and female percentages in the body composition calculator are as follows:
|Body Fat % =
|Body Fat % =
|s = sum of 7 skin-fold mm
a = age
Body Fat % Categories
The American Council on Exercise lists the following body-fat percentage categories:
|Essential fat||10% to 12%||2% to 4%|
|Athletes||14% to 20%||6% to 13%|
|Fitness||21% to 24%||14% to 17%|
|Acceptable||25% to 31%||18% to 25%|
|Obese||32% or higher||26% or higher|