How To Measure Body Fat Percentage: 8 Accurate Techniques

Many people have scale anxiety, meaning that they dread stepping on the scale and seeing how much they weigh.

As a society, we tend to place a lot of value on how much we weigh, but it’s important to remember that your body weight, size, and composition have nothing to do with your worth and merit as an individual.

With that said, at least part of the anxiety about stepping on the scale is likely due to the fact that body weight tends to fluctuate a lot and isn’t necessarily even that indicative of your health.

But what about your body fat percentage? First, we need to learn how to measure body fat percentage.

Measuring your body fat percentage can be a more useful biometric to track because it’s often less sensitive to daily fluctuations in fluid volume, and your body fat percentage is really what can influence your health, rather than your overall weight, which also includes lean body mass.

So, what is the best way to measure body fat percentage? How accurate are body fat scales? In this article, we will discuss how to measure body fat percentage and the best way to measure body fat percentage at home.

We will cover: 

  • What Is Body Fat Percentage?
  • How To Measure Body Fat Percentage: 8 Techniques

Let’s get started! 

Skin fold calipers. How to measure body fat percentage.

What Is Body Fat Percentage?

Body fat percentage refers to the relative amount of total body fat (adipose tissue) you have in your body compared to lean body mass, so when measuring your body fat percentage, you are essentially determining how much of your total body weight is fat tissue. 

For example, if you have 18% body fat, 18% of your total mass or weight is fat (subcutaneous fat under the skin and visceral fat surrounding the organs in the abdomen), while 72% of your mass is lean tissue like muscle, bone, nerves, blood, cartilage, organs, etc.

In practical terms, if you weigh 165 pounds (75 kg) and have 18% body fat, you have 165 x 0.18 = 29.7 pounds of body fat.

How To Measure Body Fat Percentage: 8 Techniques

There are quite a few different ways that you can measure your body fat percentage.

However, if you are looking into how to measure body fat percentage at home, keep in mind that many of the best ways to measure body fat in terms of accuracy require laboratory equipment, so they can’t be performed at home.

Skin fold calipers. How to measure body fat percentage.

Instead, most of the best at-home body fat percentage measurement methods are estimations of body fat percentage, but this isn’t to say they aren’t accurate enough to be worthwhile.

Here are some of the best ways to measure body fat percentage:

#1: Hydrostatic Weighing

Hydrostatic weighing, also called underwater weighing, is the gold standard for measuring body fat percentage.

It’s an involved process that requires specialized equipment in a lab, so it’s not a viable way to measure body fat percentage at home.

Hydrostatic weighing involves submerging the person in a tank of water after he or she expels all of the air from the lungs.

Weight is recorded under water and a measurement of the amount of water displaced. These values are then used to help calculate your body size and body density.

Because fat tissue is a lot less dense than lean body mass, the body density and body size can then be used to calculate the body fat percentage.

As can be surmised, this relatively invasive body fat measurement test is not feasible or appealing to most people.

Infrared: How to measure body fat percentage.

#2: Whole-Body Air-Displacement Plethysmography (BOD POD®)

This is a laboratory tool that uses air displacement to calculate the total volume of the body, which can be used with body weight to calculate body density and, thus body fat percentage.

It uses the same principles as hydrostatic weighing but uses air displacement instead of water.

#3: Infrared

This method of measuring body fat percentage involves placing a specialized infrared-light-emitting probe against an area of the body to assess fat mass and fat-free mass based on light absorption and reflection.

#4: Dual-Energy X-ray Absorptiometry (DEXA)

While this type of machine is best known for measuring bone mineral density, it can also measure body density and fat mass, which can be used to calculate body fat percentage.

For males, there’s a 4-site skinfold equation for calculating body fat percentage.

Skin fold calipers. How to measure body fat percentage.

#5: Skinfold Calipers

One of the most common ways of measuring your body fat percentage in gyms or other fitness settings is by using skinfold calipers. 

Measuring body fat percentage with skinfolds involves using precise calipers to measure the thickness of pinches of skin and subcutaneous fat at specific sites around the body. 

Research-based equations are then used to derive your estimated body fat percentage based on typical body fat distribution patterns.

The skinfold sites for this equation are as follows:

  • Abdomen: The abdominal site is 5 cm to the right of the belly button. Make a vertical pinch of fat and place the calipers directly below the pinch where your fingers are.
  • Triceps: This body fat site is on the back of the arm in the center of the triceps muscle, halfway from the elbow to the bony actinium process in the shoulder. Relax the arm, place the palm facing forward, and take a vertical pinch.
  • Thigh: The thigh measurement is taken on the front of the thigh, halfway from the kneecap to the inguinal fold in the groin. Take a vertical pinch.
  • Suprailiac: Although a bit hard to explain, this skinfold site is on the front/side of the hip just over the hip bone, oriented mostly horizontally or sort of parallel to the downward curve of the hip towards the belly button.
Skin fold calipers. How to measure body fat percentage.

Measure each site in millimeters and then add the sum of the four sites together.

Here is the Jackson & Pollock % body fat equation for men:

  • % Body Fat = (0.29288 x sum of skinfolds) – (0.0005 x square of the sum of skinfolds) + (0.15845 x age) – 5.76377.

Again, make sure you use millimeters.

Here is Jackson & Pollock % body fat equation for women:

  • % Body Fat = (0.29669 x sum of skinfolds) – (0.00043 x square of the sum of skinfolds) + (0.02963 x age) + 1.4072.

There is also a 3-site skinfold equation for women that drops the thigh measurement:

  • % Body Fat = (0.41563 x sum of skinfolds) – (0.00112 x square of the sum of skinfolds) + (0.03661 x age) + 4.03653.

It’s important to note that using calipers to measure body fat percentage takes some skill and technique.

Accuracy drops significantly if you don’t get the anatomical sites precise or you don’t pinch the fat correctly.

Make sure you are working with an expert trainer before you put a lot of stock into your body fat percentage values from skinfold.

A  person weighing themselves on a body fat scale.

#6: Bioelectrical Impedance

Body fat scales use bioelectrical impedance analysis to measure body fat percentage. 

The principle behind this method of measuring body fat percentage measurement is that fat mass, and fat-free mass have different resistances to electrical current.

When you step on a body fat scale, a small, harmless electrical current is sent through the body.

The electrical current flows more easily through body tissues that contain more water (blood, muscle, urine) than drier mass (fat and bone).

A body fat scale then can predict the percentage of body fat by combining the bioelectric impedance measure with other inputs such as weight, height, sex, age, and fitness level.

A  person weighing themselves on a body fat scale.

#7: Circumference Measurements

Circumference measurements involve using a measuring tape around specific locations around the body, such as the abdomen, neck, thigh, and upper arm. 

As with skinfolds, the measurements are then plugged into equations or calculators to estimate body fat percentage.

#8: Waist-to-Hip Ratio

Research shows that a waist-to-hip ratio (the circumference at the waist versus the circumference at the broadest part of the glutes/hips) of greater than 1.0 for men and 0.85 for women is associated with an increased risk of cardiovascular disease, diabetes, and cancers.

Because most of the techniques to measure body fat percentage involve algorithms or some degree of estimation, there is an inherent measurement error of +/- 3%, and this number can be even further off if poor technique is used.

For example, circumference measurements need to be taken at exact sites and using the right level of tension on the tape.

The key to getting more accurate body fat measurements is to follow the directions and protocol for the method you are using to a T and to stay consistent in the way you measure your body fat. 

For instance, if you are using a body fat scale, weigh yourself at the same time each week according to the recommended instructions.

Now that we know how to measure body fat percentage, what do we do with this information? What is a healthy body fat percentage?

You can interpret your body fat percentage values here.

A body fat scale.
Photo of author
Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, and contributes to several fitness, health, and running websites and publications. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

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