If you’re eating healthy, exercising regularly, but the scale isn’t moving, it’s time to measure your body fat percentage.
Here’s the truth.
When getting in shape, monitoring your body fat is as important as monitoring your overall weight.
I’d go as far as to say that it’s a better way to track your progress.
How come? Regular exercise, especially high-intensity training or weight lifting, can build muscle. The increase in muscle mass can make the scale stay stale or, in some cases, increase.
How come? Simple. The average bathroom scales cannot distinguish between muscle, fat, and water. After all, when we talk about weight loss, we actually mean fat loss. The typical scale isn’t designed to detect that.
Don’t worry, though.
There are many ways to assess your fat percentage progress, with some methods being more accurate than others.
In today’s article, I’ll explain some of the best ways to calculate body fat and how to accurately measure body composition. More specifically, I’ll dive into the following:
- What is body fat percentage
- What’s the difference between body composition and body fat
- The importance of keeping track of body fat percentage
- The Factors That Impact Body Fat Percentage
- BMI Vs. Body fat percentage
- What’s the best way to measure body fat percentage
- And so much more.
Let’s get started.
What is Body Fat Percentage?
First things first, what do I mean by body fat percentage?
Body fat percentage refers to a measure of how much of your whole body mass is made up of fat versus other lean tissue. The metric has nothing to do with your muscle mass, which is why two people with similar body fat percentages can look completely different from each other.
In other words, it’s the amount of fat in your entire body, compared to everything else, such as your:
Let’s assume that you weigh 180 pounds and have 35 pounds of fat, and your body fat percentage is 19 percent (35/180).
Then you decide to start heating healthy and lifting weights regularly until you were able to increase your weight from 180 to 190 pounds with only three pounds of extra fat gain.
In this case, your new body percentage would be roughly 20 percent (38/190).
Now let’s assume that you stopped going to the gym and lost 10 pounds of muscle but no fat; your body fat would be approximately 21 percent.
This means that your body fat percentage is constantly changing, whether when gaining/losing fat as well as when gaining/losing muscle.
The Significance of The Number
On its own, body fat percentage means little, but when you wrap your head around the factors behind the number, it becomes super important.
Your body fat percentage is one of the most reliable and useful metrics for keeping track of your overall fitness and health. It’s more relevant than your body weight and even more than your body mass index (more on this later).
Let me explain more.
Why do you Need To Keep Track of Body Fat Percentage
Though most people often focus on the scale when getting in shape, body composition is a much more useful number to track.
Here’s why. The scale doesn’t tell the whole story. Exercise regularly, and your body composition will change as you gain more muscles and lose fat. The scale won’t reflect that change.
But tracking your overall body fat can tell you how well your program is working
It also tells how much fat you need to lose, helping you set realistic goals.
In other words, it’s possible for your scale to remain unchanged, even as you get fitter, especially if you’re gaining muscle and losing fat.
That’s why, for instance, a bodybuilder will have more muscle than is typical for his weight. Not only that, the classic body mass index may rank them as overweight despite having low body fat.
Regardless of how much you weigh, the higher your body fat percentage, the higher the risk to develop obesity-related diseases, such as heart disease, type II diabetes, high blood pressure, stroke, etc.
The Factors That Impact Body Fat Percentage
Many variables influence fat percentage.
For example, men and women have different amounts of body fat percentage due to the physiological differences between the sexes.
That’s why a super athletic bodybuilder in the cutting phase could have a body fat percentage as low as 4-5 percent, whereas a female athlete of the same caliber would only get as low as 8 to 9 percent.
The main variables that affect body fat percentage include:
- Activity level
- Activity amount
So, where does all the fat in your body come from?
Of course, the food you eat. Carrying extra pounds means that you’re taking in more calories than you’re burning.
The additional fuel is stored in adipose tissue all around your body in the form of triglycerides. Tiny amounts are also deposited in your muscles and liver as glycogen.
Fat Storage Explained
Overall, fat cells can be stored in three ways: essential, subcutaneous, or visceral fat.
Essential fat, as the name implies, is essential for a functional, healthy body. In other words, it’s the minimal amount of fat required for survival.
Subcutaneous fat is found under the skin and makes up most of our bodily fat.
Last but not least, visceral fat is found deep in the abdomen nestled among your major organs. In excess, this type of at can be extremely dangerous and can increase your risk for many diseases.
Additional resource – Here’s how to lose body fat.
Body Fat Vs. Body composition
Although they sound interchangeable, body composition and body fat are not the same measures.
Body composition, in simple terms, is the proportion of muscle, fat, bones, and water in your body. The metric breaks down your body into its distinct components, including muscle mass, body fat mass, bone, tissue, and water.
In other words, body composition is basically dissecting exactly what the human body is made up of.
On the other hand, as I’ve already explained, body fat percentage is the amount of fat you’re carrying relative to everything else. This makes it a component of body composition.
Measuring body fat doesn’t reveal much about the proportions of lean body mass/fat-free mast, as it’s the case when taking a body composition test.
Additional Resource – Your guide to running and sex drive.
Body Fat Vs. BMI
Before we get into how to calculate body fat, let’s quickly explain the difference between body fat percentage and body mass index.
Body mass index estimates body fat based on your height and weight. This, in turn, makes this metric a consistent indicator of your overall health. And the reason health professionals have used this index is to determine whether you’re underweight, normal weight, or overweight.
Overall, a higher BMI in an untrained individual is closely related to the body fat they carry.
To figure out your BMI, you simply divide your weight in pounds by height in inches squared, then multiply it by a conversion factor of 703.
The higher the number, the more overweight you’re and the higher your risk for health problems.
The CDC has these BMI recommendations for adults
|18.5 – 24.9||Normal or healthy weight|
|25.0 – 29.9||Overweight|
|30.0 and above||Obese|
BMI cannot measure body fat as it doesn’t distinguish between fat and lean muscle weight. The metric uses weight and height in the formula, but sadly it doesn’t account if your weight comes from lean muscle rather than fat tissue—or the other way around.
For example, bodybuilders with a lot of muscle mass could have a high body mass index based on their weight and height. But that doesn’t make them less healthy.
For these reasons and more, if you want a clearer picture of your body fat percent, you have to measure it directly. That’s where the rest of this article comes in handy.
How To Measure Body Fat Percentage
Now we got the definitions out of the way, let’s delve into the many methods used to measure body fat percentages.
1. Pictures And Mirror
This is one of the easiest ways to estimate body fat percentage even though it’s not that exact, and it also requires a trained eye. By taking pictures from week to week and comparing the progression, you can virtually guestimate what your body fat percentage is.
You can pretty much get a close estimate of your body composition simply by checking your pictures. Why? Simple.
The visual appearance of different body fat percentages can differ depending on how much muscle you have.
Your muscle mass plays an important role in determining how you’ll look.
In other words, if you’re losing fat and gaining muscle, you’re going to look better and better, no matter what the scale or anything else is saying.
For example, an average person at 180 pounds and 25 percent body fat has about 45 pounds of fat.
A ripped athlete at 180 pounds and 8 percent body fat has only 14 pounds of fat. As you can already tell, these two are going to look very, very different.
This method isn’t a reliable way to measure body fat percentage, but it’s a good way to keep track of your progress. Pictures, after all, don’t lie.
Make sure to take your pictures in front of a plain white wall or a solid background. And remember to take more than one picture.
Next, take front, side, and back pictures. Use the same angles and body positions every time. And try to take the pictures at the same time, preferably on the same day. Be consistent.
For better accuracy, use a digital camera or your phone. I’d recommend asking a friend or spouse to snap your pic.
Are you taking the pics yourself? Put the camera on a flat surface and set a self-timer.
2. Waist Measurements
The amount of fat you’re carrying around your waistline says a lot about your health.
Even if you have a relatively healthy body mass index, you could still be carrying excess belly fat. This may put you at a higher risk for diabetes, heart disease, and stroke.
Of course, don’t my word for it.
Research has reported that men with a waist reading of more than 40 inches (101.6 cm) and women with a waist measurement higher than 35 inches (88.9 cm) are at a higher risk for diabetes and cardiovascular disease.
Additional Reading – Does running give you abs?
This method’s accuracy can vary based on your similarity to the people used to form the equations.
When performed properly, the error rate can typically be within 5 percent of the body fat value measured using underwater weighing—one of the most reliable s ways of assessing body composition.
This method is only an estimate of body fat— not a reliable measurement of total body composition.
The equations are not universal. For example, people have different shapes and fat distribution, making body circumferences equations less accurate.
The method is simple.
Get a measuring tape, then take the readings at specific spots, such as your waist, forearm, and hip. At the very least, repeat the measurement process three times for an average reading.
Next, input the measurements (along with your height and gender) into a calculator, like this one. And voila!
3. Skinfold Calipers
Skinfold calipers are relatively cheap (around $10 a pair), making them one of the most accessible methods for measuring body fat.
Often employed by fitness experts and coaches, this method measures the thickness of the subcutaneous fat, the fat underneath the skin by pinching the skin fold.
The test is performed at specific body sites, either using three, four, or seven parts (different sites for men and women). The measurements are given in millimeters and compared to a chart according to age and gender.
The accuracy varies depending on the skill of the person taking the measurements. Error margin can range from 3 to 5 percent body fat.
The accuracy of the measurement depends on the expertise of the person taking the readings. That’s why you should have the same person taking the measurements each time. It’s also hard to get a reliable reading if you’re obese.
The test requires two people.
Your assistant—whether your spouse, friend, or coach—starts by pinching your skin at the specific sites. Each protocol has specific body parts for measuring, including the thighs, belly, arms, and chest.
After inputting the readings into a formula, you can estimate your body fat percentage.
Test on the same side to minimize error, using the same spots every time. You should also take an average of three readings at each site.
Here’s a YouTube Tutorial:
4. Dual-Energy X-Ray Absorptiometry (DEXA) Scans
Although used to measure bone mass for osteoporosis diagnoses, A Dexa scan can also be used for body composition.
As the name implies, the DXA scan works by sending low x-ray beams throughout your body. By gauging the absorption rate of each beam, the technicians can measure fat mass, lean body mass, and bone mineral density.
The method is safe and quick—roughly four minutes, and it’s done. It not only tells you how much fat you’re carrying but also how it’s distributed around your body.
This test can also examine the bone density and offer information about the bone, lean mass, and fat in different body regions, such as the torso, legs, and arms.
Taking a DEXA scan involves making an appointment with a medical professional.
Depending on your location, the scan can be expensive and might not be covered by insurance. Expect to pay around $140 or more for the accuracy. But, of course, the high level of accuracy comes with a price tag. And yes, they also deliver tiny amounts of radiation.
The DEXA scan is considered the golden standard for body composition measurement. The error margin can range from 2.5 to 3.5 percent body fat.
To get a DEXA scan, you’ll need to find a place that has the machine, usually available in medical or research centers.
During the test, you lie still on a table on your back for roughly 10 minutes while the machine’s rays scan you over.
5. Hydrostatic Weighing
Also known as underwater weighing or hydro densitometry, this method measures your body composition based on its density.
The premise is simple. Bone and muscle are denser than fat. Therefore, if you have a high body fat percentage, you’ll weigh less underwater relative to the amount of water you displace.
Hydrostatic weighing compares your normal bodyweight—outside of the water—to your bodyweight while fully submerged.
By assessing these two numbers and the density of the water, the technicians—usually medical professionals—can accurately estimate your body’s density. Then your body’s density is used to estimate your body fat percentage
To minimize error during the test, you’ll need to forcefully breathe out as much air of your lung as possible while still fully submerged underwater. For some people, this might be a problem.
People with denser bones, such as some elite athletes, may not get an accurate measurement, too.
Just like with a DEXA scan, you’ll need to find a research center or lab that has the equipment.
The error margin can be as low as 2 percent body fat when performed properly.
You’ll be first weighed on dry land. Next, you’ll slowly enter a large tank of water. Then, while sitting on a special scale, you will be lowered into the tank until you’re fully submerged.
Next, you’ll be asked to exhale as much air as possible from your lungs then stay motionless while your underwater weight is taken. The test is repeated three times for an average result.
6. Bod Pod
Similar to underwater weighing, the body pod measures your body composition based on the density of your body. But, instead of water, this method relies on “displaced” air.
You’re weighed before sitting in a small pod machine, then weighed again while sitting on the machine. By gauging the amount of air displaced while on the pod, the technicians can measure your body density, therefore, deduce your body composition.
The method is non-invasive, safe, and quick. It’s super accurate and reliable for repeat tests. It does not require getting radiated or getting wet.
This method is also suitable for people of all ages, sizes, and shapes and is reliable for groups including the obese, elderly, children, and disabled people.
Research has reported that the Body Pod’s accuracy is similar to underweight weighing. The range of error for this is around 1-2.7 percent.
Hard to find. The machine is exclusively available at a few research centers and academic institutions. The test isn’t cheap—costing around $100.
You’ll need to fast two hours before the test and wear skin-tight clothing during the test for an accurate reading.
Next, you sit and remain motionless inside the pod bod—an egg-shaped chamber—for a few minutes while the air pressures inside the Chambre are altered over regular intervals.
7. Bioimpedance Spectroscopy (BIS)
The Bioimpedance Spectroscopy method uses electrical current and high and low frequencies to accurately measure the amount of body fluid.
The premise is simple.
Muscle mass conducts electrical currents easier than fat due to the higher water content of muscle.
The technology works by detecting how your body reacts to small electrical currents. This is performed by placing electrodes on your skin. Some send small currents into your body, whereas others receive the signal once the current has passed through your body tissue.
By sending a small current between two conductors, the technicians measure the resistance between the two to get an accurate image of your body composition.
How accurate this method largely depends on how similar you are to the people used to develop and form the equations. So results could vary.
8. 3-D Body Scanners
The 3-D body scanners method relies heavily on the shape of your body. The method employs infrared sensors to get a thorough picture of the shape of your body. Then the sensors create a 3-D model of your body.
Although the method may seem similar to the body circumference methods, you get many other details that help for a more accurate estimation of body composition.
A 3-D body scanner is considered a highly accurate way to measure body composition with an error rate of only 5 percent.
The method uses advanced infrared scanners to get a thorough look at your body shape. Some devices use sensors that rotate around the body, whereas in others, you’ll need to stand on a spinning platform for a few minutes while the sensors analyze your body shape.
Next, a 3-D structure of your body is created to get a clear picture of the required details.
9. Multi-Compartment Models
This all-encompassing method is considered the most accurate method for assessing body composition.
The Multi-Compartment Models method breaks down your entire body into three parts to obtain the needed measurements. It measures physiological mass, bone density, body volume, and water content.
Data from these models is collected to create a more thorough and complete picture of the most accurate body composition measurement.
As you can already tell, the method isn’t cheap—at all.
Super accurate. The error rate can be around 1 percent overall.
Just like discussed earlier, accuracy comes with some inconvenience. For starters, don’t expect to find the 4-part Multi-Compartment model machines at your local gym.
The method, as you can already tell, isn’t that cheap.
The Multi-Compartment Models method measures your body composition using the best approach for each component by obtaining information from some of the methods and techniques already discussed.
For example, hydrostatic weighing or Bod Pod is used for body volume, Dexa is used for bone content, etc.
Your Next Step
So what should you do next?
Here’s my best advice. If you’re going to start measuring your body fat percentage, make it a rule to test yourself under the same conditions, using the same method(s) each and every time.
For example, every Saturday morning on an empty stomach.
This way, even if you’re not using the most accurate method, you’ll, at the very least, get a consistent, less-than-accurate reading and can tell how much you lost or if you’re heading in the right way.
For convenience and cost, I’d recommend that you use a combination of progress pictures, caliper measurements, and the scale. Then, once you have the time and resources, try a Dexa scan or Bod Pod for a more accurate reading.
Next, compare and contrast and see how accurate your initial measurements were.
How to Measure Body Fat Percentage – The Conclusion
Keeping track of your body fat percentage is one of the best ways to check on your progress—or lack therefore. And this is the case whether you’re exercising to lose weight, build muscles, or simply stay in shape.
The methods above should provide an objective picture of your current fitness and health status.
As you’ve seen in this article, measuring your body fat percentage isn’t rocket science. Sure, you may need to spend some money on accuracy, but it’s not that much overall.
Plus, it isn’t something you will be doing every day. A couple of tests per year are more than enough.