The subject should be standing upright with weight evenly distributed on both feet.
1. Mark the spot.
First mark the xiphoid process - the lower tip of the breast bone. It is the bony spot where your ribs meet at the center of your chest.
Next mark the spot on the midaxillary line at the level of the previous mark. The midaxillary line is an imaginable vertical line between the armpit and the hip.
2. Pinch the skin. Using your thumb and index finger, grasp a vertical fold approximately 2 cm above the mark.
3. Position the caliper: Ensure that the mark remains centered between the caliper tips and that the jaws sit perpendicular to the length of the skinfold.
General rules: taking skinfold measurements.