Calculate Body Fat: A SIMPLE Step By Step Guide

Calculate Body Fat A SIMPLE Step By Step Guide

You might be weighing yourself once a month, once a week or even every day.

You might also be calculating your body mass index (BMI) every now and then. But what if the extra weight you see on the scale was mostly muscle?

If you have a low body fat percentage, a heavy muscle mass and strong bones, you might be wrongly classified as overweight, because your BMI (and weight) would be high.

A good way to know is to measure your body fat percentage, fat mass and fat-free mass.


How Do I Measure & Calculate Body fat?

The word ‘Fat’ often comes with a load of negative connotations. But as any nutritionist will tell you it is an important part of the human diet.

However, as 62% of adults in the UK are overweight or obese, people in general seem to overestimate its importance.

Body fat (or adipose tissue) is used mainly to store lipids, which provide the body with energy. As such some endurance athletes may eat foods high in fat prior to a long race or event in order to store as much energy as possible to draw upon quickly.

Certain people may find themselves being classed as technically overweight or even obese despite having a very low percentage of body fat.

Power lifters and bodybuilders find this happens quite often because of the size and density of their muscles offset with their height in calculating their BMI.

This is because the BMI formula ‘BMI = (Weight in Pounds / (Height in inches x Height in inches) x 703)’ makes no consideration for body composition or ratio of muscle to fat.

It is rare to find Athletes at the highest levels of competitive physical activity that ‘look fat’ but a peak beneath the hood will show that whilst svelte and lean. These individuals have painstakingly calculated the precise percentage their bodies need to perform optimally.


Optimal level of fat ranges

This optimal level of fat ranges greatly depending on: sex, age, height and, of course. The type of sport the Athlete competes in.

Everyone’s body is different and to a degree needs a different balance of muscle and fat, with athletes. This balance can be the deciding factor between a winning and losing performance as such it is paramount to keep it in check.

Male athletes body fat percentage tends to average around 6-13% and women’s between around 14-20% (although women in general store more body fat than men do, biologically).

Though people can survive and thrive at lower body fats than that.

Unlike your BMI which can be found through a simple formula. It is much more difficult to calculate precise body fat percentage at home without the bioelectric impedance analysis. Or hydrostatic density testing you could get in certain centres. But this is not to say they are not options that can be used.

There are however estimations that can be made by measuring the circumference of limbs and trunk and running some calculations through a calculator.

Although these are going to be rough estimate and not as reliable as actual reading you could get from visiting a professional.

But below we have listed some methods that you can use to find a close enough estimation to the level you are at.

So you know what changes need to be made.


Best Ways To Calculate Body Fat:

Body Fat Calipers 

Body fat calipers measure skinfolds to see how much fat is layered underneath the skin.

The numbers found from the caliper are then used in an equation to estimate your body density and also body fat percentage.

It is important to remember that Body Fat Calipers are an estimation.

They are not going to track your body fat percentage to 0.001% of the actual number. But what they do is give you a number that you can work with. And also calculate your progress in accordance to this number.

As long as you can use this number to track your body fat percentage. And see whether this number is consistently going up or down in relation to the physical exercise that you are doing, then you will be fine.

For many people, using a body fat caliper will be the cheapest and most effective way to measure your body fat percentage. A caliper only costs a few pounds, and does not require a complex calculation.


How Do I Use Calipers To Workout Calculate Bodyfat?

Personal Body Fat Calipers are easy to use in the privacy of your home, with superior accuracy and reliability.

Since the majority of fat on the body is located directly under the skin. A very efficient and practical way to measure your body fat percentage is skinfold measurement – the scientific approach to the time-honored “pinch an inch” method.

The Accu-Measure Personal Body Fat Tester is a precision instrument. Which has been shown in clinical studies to be closer in accuracy to the “gold standard” underwater weighing than any of the more elaborate methods of measuring body fat (without the inconvenience, expense, trained personnel, and lack of privacy these methods entail).

So whether you choose to use the Personal Body Fat Tester privately or with the help of someone else, just follow the simple steps below – it’s as easy as ONE, TWO, THREE.


how to measure body fat figure 1


how to measure body fat figure 2


how to measure body fat figure 3


how to measure body fat figure 4


how to measure body fat figure 5


Step 1
The site you will use for skinfold measurement is the suprailliac (approximately one inch above the right hipbone, see figure1).

Step 2 While standing, firmly pinch the suprailliac skinfold between your left thumb and forefinger, see figures 2 and 3.

Place the jaws of the Personal Body Fat Tester over the skinfold. While continuing to hold the skinfold with the left hand, see figure 4.

Step 3 Press with the thumb where indicated on the Personal Body Fat Tester until you feel a slight click.

The slide member will automatically stop at the correct measurement, see figure 5. After reading your measurement, return the slide member to the far right starting position.

Repeat three times and use the average as your measurement.

Refer to the body fat interpretation chart to determine your body fat percentage and what it means.

Next up is,


Hydrostatic Weighing To Calculate Body Fat

For those of you who don’t mind getting a little wet, Hydrostatic weighing may be for you.

Also known as underwater weighing, Hydrostatic weighing compares your normal body weight when not in water. To your body when you are underwater.

The two different numbers taken from your weight outside of water and your weight underwater are then compared to each other and a analysts can then calculate your density.

From here, the number provided is then used to estimate your body fat percentage.

One of the advantages of hydrostatic weighing is that it is extremely accurate. And is used by many industries and laboratories for professional athletes.

Unfortunately, unless you have access to one. You will most likely have to find a university or sports science centre where you can use their equipment. Which is far more expensive than a body fat caliper.


Bioelectrical Impedance To Calculate Body Fat

Fancy names aside, bioelectrical Impedance is another method of measuring your body fat percentage.

Bioelectrical Impedance scales send electrical impulses through your body and measures how quickly those impulses return.

Depending on the response time to how quickly those impulses are returned. Your body fat percentage can be calculated.

This is due to the fact that muscle contains a high content of water, which means it is highly conductive. Whereas fat has a much lower water content, meaning that it is not highly conductive.

Lean tissue will therefore conduct electrical impulses at a faster rate than fatty tissue.Thus meaning a faster response time usually indicates a leaner physique.

Because Bioelectrical Impedance testing in based on body water balance. Sometimes the level of hydration in your body can directly impact the level of accuracy.


DEXA Scan To Calculate Body Fat

Dual Energy X-Ray Absorptiometry (what a mouthful) is known in some industries as the new standard for measuring body fat and also body fat percentage.

A DEXA scan is based on a three parted model that separates the body into three different sections: total body mineral, fat tissue mass and fat free.

A DEXA places subjects under X ray beams of changing velocities and is also used not just to measure body fat percentage, but also bone mineral density.

A machine passed over the body beams, X rays onto the subject. And by measuring how each beam is absorbed.

Technicians can gain information into your body fat percentage.

DEXA also allows for analysis of how body fat is distributed. And so you can accurately calculate which parts of your body have a higher percentage of body fat than the other.


US Navy/Circumference Method to Calculate Body Fat

Another common and cost-effective way to measure body composition is using a tape measure to calculate circumferences in regions where fat resides.

In fact, the method so common that the entire US Armed Forces uses the method to measure body composition. Like calipers, the idea is quite straightforward: as people put on fat. They tend to expand in various regions of the body.

Like calipers you can measure this expansion. Unlike calipers there’s no pinching involved.

However, using the tape measure can be uncomfortable for your member or patient. Often, the biggest obstacle though is the lack of repeatability. A result of the difficulty of finding the same spot twice when taking a measurement.



The US Navy or circumference method relies on running specific body measurements through a highly developed formula to produce body fat percentage. These measurements are taken manually at the abdomen and neck for men and at the neck, waist, and hips for women.

During its research and development stage, this formula was calibrated using data from DEXA scans and. When administered correctly, is said to produce the same amount of accuracy.

Body measurements are taken manually at designated areas with measuring tape. This measurement process is repeated three times. The average of the three measurements taken at each spot is then input into a formula to calculate an individual’s body composition. 

This very easy to use and administer on site. The formula is highly reliable when done correctly.

But they are prone to human error as the method relies on taking measurements manually. Tilt the tape measure slightly, or add a bit of slack, and you’ll find extremely varying results.

In fact, the margin of error can be as high as 10% just due to human error in measuring with a tape. 

Ultimately, the science is sound, but the instrumentation is lacking in sophistication.

If paired with digital circumferences, like those from body scanners. Then this method can be the new gold standard, and for that alone, it gets a better grade than Calipers. 


Bod Pod To Calculate Body Fat

The Bod Pod is an egg-shaped device that measures body volume and bodyweight to determine body density and body fat.

Step on a scale outside the device to get your weight. Then, the tester measures the air volume or pressure of the empty Bod Pod.

Get into the chamber, and let the machine measure the air volume with you in it. Now, it’s time for some math. Empty Bod Pod air volume – Bod Pod air volume with you inside = your body volume.

Body density = your bodyweight/body volume.

The accompanying Bod Pod software uses density to estimate body fat percentage. It’s similar in accuracy to underwater weighing and more practical, but it’s expensive.

A Bod Pod costs around £28,000.

Find a testing center by simple googling bod pod near me. And they will all pop up they vary from £40 – £100 depending on the length of the session which is usually around 30 mins. 


They all work

What can be gained from all of this is that all these methods are effective ways for you to measure your body fat percentage.

From simple body fat calipers to a Dual Energy X-Ray Absorptiometry scan. What it depends on is your access to certain facilities, and also the accuracy you require.

If you would simply like a method to track whether you are reducing your body fat percentage as you embark on your new fitness regime, then a body fat caliper will do just fine.

For those who wish to know the exact percentage of fat in your body. 

Either way, keeping track is a good way to know the progress you are making in your quest for a leaner body!


Bonus #1: What is the Difference between BMI & Body fat percentage?

What is BMI (Body Mass Index?)

BMI or Body Mass Index is a simple measure of a person’s weight in relation to his or her height.

Your BMI is not a percentage of your body fat, but just a score that helps ascertain if you are fit.

If you have too much weight for your real height, the difference in weight is usually assumed to be excess fat.

Even though many health care providers claim that body mass index is not an accurate measurement. It is the least expensive and the easiest way to ascertain if your body fat is too high or too low.

Generally a BMI of 25 or higher is considered overweight and you will be at a high a risk of high blood pressure, diabetes, heart disease and other serious illnesses.


What is Body Fat Percentage?

Your body fat percentage is your total fat divided by your weight.

The measurement helps you determine what percentage of your body is fat. What percentage is bone, organs, blood and muscle.

For instance if a person has 15 pounds of fat and weighs 150 pounds. He or she has a body fat percentage of 10 percent.

Body fat percentage not only changes automatically when you lose or gain fat. It also changes when you lose or gain muscle.

In addition, both women and men have different body fat percentages.

For instance a super ripped man can have a body fat percentage of as low as 3 to 4 percent while a super ripped lady can only get to 8 or 9 percent.


So What Is The Difference?

The average fat is between 25 and 31 percent for women and 18 to 25 percent for men.

Also note that your fat percentage has nothing to do with your muscle mass.

This typically means that you can have 2 different people with the same fat percentage but look different.

Determining body fat percentage involves more factors than BMI.

It takes into consideration how much of a person’s weight is bone, muscle and fat, while BMI doesn’t.

This means that you can have an appealing BMI. But still carry some weight in your belly which increases your risk of heart disease.

Nonetheless most fat measurement techniques have a margin of error of between 1 to 4 percent and are not easily accessible.

Body Mass Index on the other hand can be used by almost everybody and involves a very simple mathematical calculation.