Measuring body fat is an important metric that gives insight into body composition. It represents the percentage of body weight that is made up of fat as opposed to lean body mass (or LBM). 

There are many ways to measure body fat and calipers are one practical tool that’s cheap to buy and can be used at home to take this measurement.  

What are Calipers?

Calipers don’t actually measure your body fat percentage directly but are used to measure the size of skin folds in various locations in the body.

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Then, by using one of a number of different formulas these measurements can be turned into a body fat percentage estimate. 

This is also commonly known as the ‘skinfold test‘ or ‘pinch test‘. 

Pros of Using Calipers

  • Calipers themselves are very cheap to buy and easy to source
  • When used correctly calipers are a good way of tracking changes in body composition over time

Cons of Using Calipers

  • Calipers can provide inconsistent results and have a relatively high error rate if not used by an experienced person
  • Body fat estimates are derived from formulas based on a statistical-model using national averages. Estimates will not be accurate for all people, such as athletes or those with high muscle mass.
  • Calipers may not open wide enough to take measurements in obese subjects

How to Take Measurements Using Calipers

Technique is important when using calipers to take skinfold measurements. We have compiled these guidelines to help take more accurate caliper measurements;

  1. Take measurements on the right side of the body
  2. Grab a fold of skin and use the caliper to measure thickness to the nearest 0.5mm by reading the measurement dial
  3. Hold calipers perpendicular to the skinfold
  4. The measurement point of the skinfold should be half way along length of fold
  5. Accepting measurements (ACSM method)
    1. Take two readings and if they’re not within 1-2mm of each other then retake
    2. Record measurements when 2 consecutive values are within 1-2 mm and take the average

Skinfold Measurement Sites

The different skinfold measurements sites used by the various methods are listed below;

Skinfold locationMeasurement Guidelines
AbdomenTake a vertical skinfold 2cm to the right of the umbilicus
BicepsTake a vertical skinfold over the belly of the muscle
Calf (medial)Take a vertical skinfold in the middle of the calf muscle at the point of largest girth
Chest (pectoral)For men only, take a diagonal skinfold (45 degree angle) half way between the nipple and outer chest (anterior axillary line)
MidaxillaryCan use vertical or horizontal skinfold (although must ensure consistency) on the midaxillary line (down the side of the torso) at the level of the xiphoid process (base of the centre column in rib cage). 
SubscapularTake a diagonal skinfold measured 1-2 cm below the inferior angle of the scapula (towards middle of back on right hand side).
SuprailiacTake a slightly slanted skinfold just above the iliac crest (side of body above the pelvis)
ThighTake a vertical skinfold in the midline of the right thigh. Bodyweight should be shifted to the left foot. 
TricepsTake a vertical fold on the back of the upper arm, halfway between the elbow and top of shoulder.

Body Fat % Formulas and Accuracy

Now that you know what calipers are, how they’re used, and of the different measurement sites we’re going to introduce you to some formulas to produce your actual BF estimate.

There are actually over 100 different formulas out there. Each equation relates to different populations, ages and characteristic types which skew the statistical model output. Obviously it’s best to use a formula that more closely matches your own profile. We’ve chosen two of the most popular formulas used which should work for most of our readers.

It’s also worth noting that you don’t have to convert your skinfold measurements to a body fat estimate at all. Instead you can just monitor the changes in skinfold measurements at various body sites.

Also note that there are many calculators online that will take your measurements and give you your end body fat estimate automatically. What we’re actually doing is showing your formula behind the scenes to give you insight into the factors at play.