You only need a set of skinfold calipers and a few minutes. Take all measurements on the right side of your body, ideally in the morning before exercise. Follow these steps for each site:

• Firmly pinch the skin and fat (not muscle) between your thumb and forefinger, about 1 cm above where you'll place the calipers.
• Place the caliper jaws on the fold, release the trigger, and read the value after about 2–3 seconds.
• Take 2–3 readings at each site and use the average. If readings differ by more than 2 mm, measure again.
• Enter all measurements in millimeters (mm).

The measurement sites:

• Chest: Diagonal fold, halfway between the armpit crease and the nipple (men), or one-third of the way for women.
• Abdominal: Vertical fold, about 2 cm to the right of the belly button.
• Thigh: Vertical fold on the front of the thigh, midway between the hip and the kneecap.
• Triceps: Vertical fold on the back of the upper arm, midway between the shoulder and elbow.
• Suprailiac: Diagonal fold just above the hip bone, in line with the natural angle of the iliac crest.
• Subscapular: Diagonal fold just below the bottom tip of the shoulder blade.
• Midaxillary: Vertical fold on the side of the torso, in line with the middle of the armpit, at nipple level.

The 3-site test is quicker and uses different sites for men and women. The 7-site test uses all sites above and is slightly more accurate.

The following sites for both the 3-site and 7-site tests are listed based on the most logical progression to take the measurements starting from chest and working your way down to the thigh.