How to Measure Body Fat

How to measure body fat

During weight loss, the goal is to reduce body fat and maintain/ increase muscle mass. Therefore, scales don’t provide a clear picture of what is happening. They don’t tell you how much of your weight is fat and how much muscle. Also, your daily water levels vary, which can further confuse what is really going on.

How much should I weigh?

The only way to get a clear picture during a weight loss program is to measure body fat composition, i.e. body fat and lean body mass. It is easy for people to mistake activity for achievement. Simply because you are in the gym and dieting does not mean that you are losing body fat, you need to be certain that during your weight loss program you are experiencing fat loss and not muscle loss!

It could be the case that looking at yourself in the mirror may be enough for you to monitor your progress, as after all that is what determines whether you are happy with your physique. However, many of us have some degree of distorted body image and need to be careful that we are not aiming for a physique that we cannot attain and thereby placing our health in danger. Hence, an objective, scientific and accurate method of measuring ones progress is best.

Methods of Measuring Body Fat

These are some options on measuring body fat percentages:

Bioelectrical Impedance (BIA):

This is considered one of the the more exact and accessible methods of screening body fat. Weight, height, age, gender and other physical characteristics such as body type, physical activity level, ethnicity, etc. are taken into account. While you are lying down, electrodes are attached to attached to the extremities of your body and a small electric signal is circulated (don’t worry you can barely feel it!). Electrical and resistance measurements are obtained from this and converted to lean and fat mass measurements. Best results are obtained in the early morning with no alcohol consumed for 24 hours prior and no exercise the night before. You can have these done cheaply at a local gym or university.

Body Fat Scale:

Can buy these and use at home. Convenient, but not very accurate, reading may fluctuate. Best probably made by Tanita.


Estimating body fat by measuring limb circumferences with a tape measure. Equations are used to calculate body fat percentage. Will give a ballpark figure. Use the body fat calculator.

Skin-fold Testing:

Measurements taken by pinching skin in six different places with a skin-fold caliper. The results are plugged into a formula to determine your body fat. You can either get an expert to do this or do it youself. The DIY approach can be quite accurate, but depends on your ability to accurately measure. Practice makes perfect! Measuring body fat with a set of body fat calipers oneself is the most cost effective way to determine body fat levels and is an easy, portable and convenient process, which can be performed in the privacy of your home at any time you wish. The margin of error may be slightly larger than with a skilled professional. Calipers by Accumeasure are the only calipers that allow you to measure yourself and most studies have shown them to be very accurate. Take 3 readings and then calculate an average.

There are other methods such as DEXA scanning (full body X-ray scan) and hydrostatic weighing (completely submerged under water). Both these methods are very accurate, but expensive and not easily accessible.

The importance in all these techniques is not as much complete accuracy (for example it does not particularly matter if your body fat percentage is determined to be 18% and it actually is 20%) as being able to chart your progress accurately over time. In truth, this is the chief purpose of body fat testing – to measure progress. The other advantage of monitoring your progress by determining body fat percentages is that it also allows you to calculate you lean body mass (LBM). LBM includes any fat-free tissue, i.e. muscle, bone, organs, etc.