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How to Test Your Body Fat: The Ultimate Guide

By Tory Reiss / May 27, 2014

body-fat-measurement-tools

So you want to know your body fat percentage, huh? Great! You came to the right place.

Measuring body fat can be really confusing for a lot of reasons. For one, there is seemingly a ton of different testing methods available – some of which are simple and inexpensive and others that are costly and invasive. For two, a lot of the results can be inaccurate and less than reliable which can make it difficult to get the data you want for self-assessment. If that wasn’t confusing enough, most of the body fat testing methods have long scientific names that can just plain sound scary and complex.

Let’s make it simple. I’m going to help you make sense of measuring your body composition; understand why it’s important, how it can help manage goals, and which method is right for you.

What is body fat percentage?

Let’s begin with the basics. Simply put, body fat percentage is the ratio of fat mass in your body in relation to lean mass. Bones, muscle, and organs represent your lean mass and adipose tissue (fat stores) makes up your body fat mass. All women have a higher level of body fat than men because their bodies are designed for childbearing and other functions.

Why test your body fat?

Looking at yourself in the mirror is a great way to measure progress, don’t get me wrong. Sometimes we are too close to our own projects. We look at ourselves every single day and sometimes can’t notice small changes that may seem insignificant and we can become lost or lose motivation if changes aren’t happening quick enough to be noticeable.

That’s where body fat testing comes into play.

Sometimes we just want some tangible numbers that we can look at from week to week and make a definitive conclusion if we are making real progress towards our fitness goals. Sure, we can get on a weight scale and see if we are losing or gaining weight on a day-to-day basis but those numbers can leave a lot of questions on the table. You might say to yourself “OK – I lost weight. How much of that weight was actually fat? Was it just water weight, waste, or muscle?”

By leveraging one of the methods below, you’ll be able to answer that question more concisely. You can use the number to determine where stand today and where you would like to be tomorrow.

What is an ideal body fat percentage?

The important thing to understand is that there is no singular number or one-size-fits-all range for everyone. This number varies greatly between gender, age, and height. Let’s dig into some average ranges that will give you at least give you some ranges in which you can build goals around.

Body Fat Percentage Chart

Body Type

Women

Men

Essential Fat*

10–13%

2–5%

Athlete

14–20%

6–13%

Fit

21–24%

14–17%

Average

25–31%

18–24%

Obese

32%+

25%+

*Essential body fat is the bare minimum requirement for human function and generally isn’t achievable, healthy, or sustainable.

How can you use these ranges to benchmark your progress and build goals? Here’s an example. Let’s say you’re a man and you weigh 200lbs right now. You have your body fat tested and determine you are 25% body fat. With these numbers we can make a few assumptions:

1) 25% is in the obese range. If we lose some fat, we can progress into the average, fit or athletic range.

2) 25% of 200 is 50lbs of fat mass. You have about 150 pounds of lean mass which again includes muscle, bone, and organs.

3) To become fit, we would have to lose about 16 lbs or 8% of current body fat.

4) To become athletic, we would need to lose about 24 lbs, or 12% of current body fat.

This is a good general guide, but it’s important to understand that your goal will often be a moving target. Typically your lean mass will decrease slightly as you lower your body fat. Why? The reason is because your body burns more than just fat as you lose weight – it burns muscle too in a process known as catabolism. Your bone density may change slightly as well. It’s important to periodically re-establish your body fat percentage throughout the fat loss process in order to reassess your lean mass to fat mass baselines.

“OK! Tell me how to do the test!”

There are five popular testing methods that each present their own advantages and disadvantages. Let’s discuss the pros and cons of each method and what you can expect from each testing method.

Bioelectrical Impedance Analysis

BIA

Sometimes called BIA or body fat analyzers for short, this method is an inexpensive and simple way to estimate body fat. Here’s how it works: Depending on the device, you either stand on a scale or hold a handheld device. Each point where your skin touches metal acts as a conductor. The device sends a small electric current (You cannot feel it, don’t worry it doesn’t hurt!) through your body. The device measures the resistance between the two points of contact. Because muscle mass is a good conductor and fat mass is a poor conductor, it can estimate your body fat based on the recorded resistance. I own the handheld Omron Body Fat Analyzer HBF-306C and use it about once a week just to keep an eye on my body composition.

Advantages:

  • Can be performed regularly at home for easy recording
  • Low cost to entry

Quick, painless, and non-invasive

Simple to use

Disadvantages:

  • Results usually differ slightly with each test and change depending on how well hydrated you are
  • Some model devices are less reliable than others
  • Can have a tendency to overestimate BF% of lean people and underestimate BF% of obese people

Where to get it done: Many local gyms or personal trainers have these devices on hand and will allow you to use them for a fee or for free when obtaining their services. As an alternative, you can purchase the same devices for your home for convenience and they are generally inexpensive.

If you are interested in picking one of these body fat analyzers up for testing at your home, here are a few of the more popular and well-reviewed BIA devices for your consideration:

How much does bioelectrical impedance analysis cost?

To test: $0-$5 on average among  gyms/trainers
To own: $35-$85 for most BIA deivces.

Video: How to test body fat with bioelectrical impedance analysis

Skinfold Caliper

skinfold-caliper-example

Also known as the pinch test, you may remember having this done back in PE class in school. This test is pretty simple. A caliper with very specific measurements is used at standard points (usually three to nine points) across the body to measure thickness.

Standard Skinfold Test Sites:

  • Triceps
  • Biceps
  • Subscapular (Upper right back area underneath shoulder blade)
  • Thigh
  • Illiac Crest (Top of hip bone)
  • Supraspinale (Love handles)
  • Abdominal (About an inch outside the navel)
  • Calf

Less commonly used sites:

  • Chest
  • Axilla (Above love handles and underneath your armpit)

The measurements are then combined to calculate an overall body fat percentage based on the results in the individual skinfold tests.

Advantages:

  • Good indicator of progress when tests performed over time
  • Most skinfold calipers are inexpensive

Disadvantages:

  • Difficult to perform an accurate test on yourself
  • Slight variances in testing locations vary results
  • Results vary from tester to tester
  • Requires some training to perform accurately
  • Doesn’t consider body fat in untested areas
  • Poor results in moderately obese persons

Where to get it done: Most gyms or weight loss clinics have trained personnel to administer skinfold caliper testing for body fat.

Most calipers will come with detailed explanations of how to perform the tests. Check out some one of these calipers if you think you want to give this body fat testing method a try. They vary widely in price depending on the quality and functionality of the caliper:

  • Slim Guide Skin Fold Caliper
  • Accu-Measure Fitness 3000 Personal Body Fat Tester
  • Harpenden Skinfold Caliper With Software

How much does skinfold caliper testing cost?

To test: $0-$20 on average among  gyms/trainers
To own: $5-$350 depending on the sophistication of the caliper.

Video: How to perform a skinfold caliper test

Hydrostatic Weighing

hydrostatic-weighing

The term hydrostatic is sort of just a fancy way of saying, “under water”. This method of body fat analysis is pretty neat. Here’s how it works: First, you are weighed precisely while outside of water to get your total “on land” weight. Then, you will sit on a specially designed scale (a sort of underwater chair) and lowered underwater into a specialized hydrostatic stainless steel weighing tank with minimal clothing while exhaling all possible air from your lungs. While underwater you can’t move. The tester is actually measuring your buoyancy and water displacement during this test. This process is usually repeated for discrepancies and a median value is used to calculate overall body fat. If you really want to get scientific, this process is known as Archimedes’ Principle of displacement.

Because fat is less dense than water, and lean tissue is more dense than water, we can actually measure the body fat percentage a person has with a special calculation. Fat does in fact weight less than muscle on a pound for pound basis, and because each has a constant mass we can measure the amount of water displacement incurred by each.

Advantages:

  • More accurate than skinfold caliper testing and bioelectrical impedance analysis
  • One of the top 3 most recognized body fat testing methods for accuracy
  • Repeat measures are generally consistent
  • Often considered “the gold standard” among body fat tests

Disadvantages:

  • The equipment used to perform this testing is expensive and may not extremely common
  • Usually more expensive per test than other body fat testing methods
  • It can be difficult to hold your breath for as long as the tester would like you too

Where to get it done:  Rarely found in most gyms. Some training facilities and universities have this equipment open to the public.

How much does hydrostatic body fat testing cost?

To test: Approximately $10-$80 per test.
To own: *Not readily available to public. Hydrostatic weighing tanks will cost a business approximately $6,000-$14,000 depending on the manufacturer which is one reason why the tests can be costly.

Video: How to perform a hydrostatic weight test

Bod Pod ADP

Bod-Pod-adp

Usually just called the bod pod, ADP stands for “Whole-Body Air Displacement Plethysmography”. Whew, that was a mouthful. This method actually works similarly to hydrostatic weighing except instead of displacing water, we are displacing air. Typically you’ll wear a special pair of underwear and tight fitted cap and be asked to sit in a pod like chamber while the tester operates a console outside and gives you instructions. I was lucky to get one of these tests done at a place called “The HIT Center” in Lexington Kentucky and I believe it cost me $70.

Advantages:

  • Does not require getting wet
  • Measurement only takes a couple of minutes
  • Safe and easy
  • Results come in a simple and easy to interpret print out
  • Highly accurate, comparable to hydrostatic weigh testing.

Disadvantages:

  • Expensive and hard to locate
  • Even less available than hydrostatic testing

Where to get it done: The health department at some universities have them available for public use. Some athletic training facilities also have them. Usually not found at a standard gym.

How much does a bod pod body fat test cost?

To test: Approximately $35-$150 per test.
To own: *Not readily available to public. The Bod Pod will cost a business approximately $25,000-$40,000 and is a primary factor in the expense of the test.

Video: How To Perform a Bod Pod Body Fat Test

DEXA / DXA Scan

dexa-dxa-scan

My personal favorite body fat test, the DXA scan is a newer method and presently the most accurate way available for getting body fat data. I had a chance to get this awesome scan done once in Ypsilanti, MI at Eastern Michigan University through the office of Nutritional Services for only $50 and was definitely an all-around great experience.

Advantages:

  • Also does not require getting wet
  • Measurement is quick and painless, non invasive
  • Results come in a simple and easy to interpret print out
  • Highly accurate, comparable to hydrostatic weigh testing.

Disadvantages:

  • Can be expensive, usually the most costly of the testing methods and usually only found at bone density test centers and universities
  • Results are usually in metric units instead of US
  • Print out can be potentially difficult to interpret, fairly scientific output

Where to get it done: Bone density testing centers usually have these scanners on-site. Your local university may have one available for public use, try a google search to see locations near you. In my experience, some testing facilities may give you a funny look or not understand why you would want this test for body fat testing only. I believe it is largely used for osteoporosis diagnostic in women.

How much does a DEXA / DXA scan cost?

To test: Approximately $50-$200 per test.
To own: *Not readily available to public. The DEXA would cost you tens of thousands of dollars and isn’t feasible to own conventionally.

Video: How To Perform a DEXA/DXA Body Composition Test

Conclusion

Having your body fat percentage on paper will give you great tangible baselines to work with in determining how much fat you have to lose and where your problem areas are. I think it can be a solid motivation tool when used appropriately over time to measure fat loss progress. Most times I would say unless you have a lot of expendable income, it’s probably worth using one of the less expensive tests to track your progress with, especially when starting out.

Side note: Never under-estimate the value of using a simple mirror, a tape measure, and your own two eyes to visualize and evaluate your fat loss!

Sources:

  1. http://en.wikipedia.org/wiki/Body-fat_percentage
  2. http://en.wikipedia.org/wiki/Bioelectrical_impedance_analysis
  3. http://consensus.nih.gov/1994/1994bioelectricimpedancebodyta015html.htm
  4. http://www.bodybuilding.com/fun/drobson98.htm
  5. http://www-rohan.sdsu.edu/~ens304l/uww.htm
  6. http://en.wikipedia.org/wiki/Hydrostatic_weighing
  7. http://ybefit.byu.edu/Portals/88/Documents/How%20Does%20The%20BOD%20POD%20Work.pdf
  8. http://www.bodycompositioncenter.com/what.html
  9. https://www.youtube.com/watch?v=wqztQryiHSA
  10. https://www.youtube.com/watch?v=6rCOi-RSAsc
  11. https://www.youtube.com/watch?v=mYv6J8-KrSU
  12. https://www.youtube.com/watch?v=5E1vCkuPiUI

 

About the author

Tory Reiss

Hi! I'm Tory Reiss. I built this blog to share my fitness quest and provide informative reviews of fitness equipment, gadgets, and supplements that you can use to help reach your health goals. Hope you enjoy it!