If you’ve been following BuiltLean.com, you know losing fat WITHOUT losing muscle is the only way to get lean. So how do you track if you are losing fat, or muscle, or both? The first place to start is by measuring your body fat percentage.
I have an overview of the 5 most common methods of measuring body fat percentage below, along with the ONLY method to perfectly measure body fat percentage (I’ll bet you don’t want to use this method). While these 5 methods vary in accuracy, the key to assessing body fat levels is consistent measurements over time (repeatability) so that you can effectively track your progress.
1) Skin Fold Caliper
The “skin fold” method measures your body fat percentage by pinching your fat with your fingers then measuring the thickness with a body fat caliper. The reading is given in millimeters, which you compare to a chart with age and gender to arrive at your body fat percentage. There are many different types of caliper tests, which range from only one site like with the Accumeasure Body Fat Caliper to a 7 site Jackson Pollack Method (some are as high as 12 sites).
Upside
- Accurate
- Dependable (when skilled at measuring)
- Repeatable
Downside
- Variability of measurement (same exact spot needs to used each time)
- More than one-site test requires a skilled fitness professional (I’ve done these thousands of times!)
- For people 35+ pounds overweight, fat may not fit within caliper, so it’s less accurate
Bottom Line
Skin Fold is hands down the most effective, accurate, practical method to measure and track your body fat percentage. The self-administered Accumeasure Body Fat Caliper retails for under $10 and is sufficient for most people.
2) Bioelectric Impedance Analysis (BIA)
BIA determines the electrical impedance, or opposition to the flow of an electric current through the body. Muscle has high water content, and is highly conductive, while fat has lower water content and is not highly conductive. Based on the strength of the impedance along with height and weight metrics, the BIA scale will estimate fat-free body mass and body fat percentage.
Many consumer weight scales like Tanita Body Fat Monitor Scale also come with BIA capabilities, and there are others that require holding the BIA device in your hands. Because the BIA test is based on body water balance, your state of hydration can impact the level of accuracy.
Upside
- Very easy to administer
- Inexpensive (most weight scales around $50 or even less have BIA)
Downside
- Questionable Accuracy
- Variability of results dependent on hydration level
Bottom line
If you can’t use calipers, this is a far second option. If you have a high body fat percentage (calipers can’t fit around your fat pinch), or you have 35+ pounds to lose, start with BIA, then move to calipers. BIA readings for those with low body fat tend to be completely inaccurate.
3) Anthropometric
This method uses body circumference measurements to estimate body fat percentages. The U.S. Navy method takes waist, neck, and height circumference for men and hips, neck, and height for women.
A U.S. Navy Method calculator is available on this website where you can input your measurements on right hand column. If you don’t have a cloth measuring tape, you can purchase a MyoTape Body Tape Measure, which I’m using to measure my waist in the picture to the right.
Upside
- Easy to Administer
- Cheap
Downside
- Questionable Accuracy (Body fat is not directly measured)
Bottom Line
I would consider this method the least accurate because it doesn’t directly measure body fat (or even attempt to). For example, I have around 6% body fat using calipers, but according to anthropometric, my body fat is around 11.5%. If you don’t have a BIA scale, or calipers, it can be a decent start.
4) Hydrostatic Weighing
This method is considered the “Gold Standard” (+/- 1.5% error) of body fat measurement that requires being submerged in a specialized tank of water. Because bone and muscle are more dense than water, a person with a larger percentage of fat free mass will weigh more in the water and have a lower percent body fat. Conversely, a large amount of fat mass will make the body lighter in water and have a higher percent body fat.
Accuracy of the reading is contingent upon blowing all the air out of the lungs during pretest screening. The test takes about 20-30 minutes, costs around $100-150, and is available at research labs, universities, or hospitals.
Upside
- Very accurate, considered Gold Standard
Downside
- Impractical
- Expensive
- Not repeatable (unless you liked repeatedly getting dunked in a tank and spending $150)
Bottom Line
If you are extremely curious to get the most accurate measure of your body fat percentage, or you are a bodybuilder, or fitness model tracking your progress, Hydrostatic Weighing may make sense. Otherwise, it’s far too impractical.
5) DEXA Scan
Dual Energy X-ray Absorptiometry known as DEXA is fast becoming the “new” gold standard of body fat measurement because it’s based on a three-compartment model that divides the body into total body mineral, fat-free soft (lean) mass, and fat tissue mass. Hydrostatic Weighing on the other hand only uses a 2 compartment model (fat free mass and fat mass).
DEXA also allows for body fat distribution analysis, so you can figure out with precision how fat is distributed in various parts of your body. In the past, DEXA was only used to measure bone mineral density for ostopenia and osteoporosis in older individuals. The procedure uses a body scanner with low dose x-rays, so it’s completely safe, and takes about 10-20 minutes.
Upside
- Very accurate
Downside
- Expensive: Around $250
- Not repeatable (unless you don’t mind spending $250 every couple weeks)
Bottom Line
Similar to Hydrostatic Weighing, if you are extremely curious to get the most accurate reading of your body fat percentage, or you are a bodybuilder, or fitness model tracking your progress, DEXA may make sense. Otherwise, it’s far too impractical and expensive.
All these methods rely on algorithms to convert a measured parameter into an estimate of body fat percentage, so none of them are perfect. Algorithms have variation based on how the underlying assumptions and formulas apply to different populations.
So what’s the only way to measure body fat with perfect accuracy? Well, cutting open a body and examining the fat, like with a cadaver. Seriously, that’s really the only way to know exact body fat percentage.
I plan on digging deeper into each method in future articles, but I hope this was a helpful overview of each method.
I use the Omron Scale to measure my body fat. It uses the Bioelectric Impedance Analysis
Thanks very informative
Wow! That is your stomach?!?!!
Haha. Yes. That picture was taken of me last week for Project Falcon, which is a fitness program I’ve been working on.
Very impressive. Great Abs!
Awesome article. Very informative. I have one of the Bioelectric Impedance Analysis (BIA) scales at home. I was searching the internet to figure out: 1: how accurate it really is and 2: what a healthy body fat percentage falls under for my gender, age, and height. This article was great. Thanks!
I’m really happy you got some value out of the article. It’s pretty dense information, but sounds like you zipped right through it!
I’m still shocked that my body fat percentage puts me in the “athletic/lean” category. I’m at 17%. Most of my life, I was a sporadic exerciser (at best) and a couch potato (at worst). Highest body fat percentage was around 30%. I got snapped into reality when my mom died of lung cancer back in ’07 because she took terrible care of herself. Nothing like your own immortality to make you put the remote down and grab a pair of dumbbells. BTW, I’ll weigh in on the whole “is that your stomach/” comment too. Impressive but I like the fact that you’re not totally bulging with muscles. Most women would agree with me, I think. Even with muscles, too much of a good thing is not attractive. Just my two cents. Thanks for the informative article too.
@Toni – thanks for your comment!
I’m a 5’7″ 156lb 42 year old woman and I’m completely confused! Using a body fat caliper on suprailiac fat places me at 22.8% bodyfat. Ok great, I’m feeling pretty good about myself. Now I step on the BIA scales and it puts me at 37% body fat!! And that supposedly is low because I have metal implants in my back which according the the Tanita website will give a slightly lower reading to body fat percentage. What a porker. Soooo, then I go to an “input your measurements/weight/height” website calculator online…and come up with….31%. Hmmm. So I have somewhere between, I assume, 22.8% and 37% body fat. Either “lean” on one end of the spectrum, or “overfat” on the other. I’m feeling a little schizophrenic. Is this kind of variation normal for different body fat measurement methods? I understand that no method is completely accurate, but this is kind of ridiculous!
@xnihilo – what you are experiencing is believe it or not completely normal. I don’t even consider BIA to a be a viable option, unless you have too much body fat where calipers don’t work. For example, I’m MAX 8% body fat, probably 7% (I have very little fat on my body) and a BIA scale calculated my at 16%. I would go with calipers hands down because you are physically pinching the fat on your body and measuring the skin folds, which is far more accurate in general, especially if done by a skilled professional. The calculators online I would definitely not pay attention to as well. If you are reasonably fit and have some muscle, at 157lb and 23% body fat, your LBM is 120lb. That sounds reasonable to me. Even 115lb LBM would put you at 26% body fat, which is within a normal range. Don’t get annoyed/frustrated/confused with these body fat measurement. Check out this article for some more info: http://www.builtlean.com/2010/08/03/ideal-body-fat-percentage-chart/.
I used the body fat analyzer on my scale for years – measured 26%. When I really got serious about running and lifting on a routine basis, my body fat percent barely budged even though I visually noticed results. I went to my chiropractor who had a different setup with a computer and lots of leads. He said it was the current gold standard (last year). It measured 16.4% BF! Moral of the story – scales are no where near accurate. Hope this helps!
@lisa – It does help. Thanks for sharing!
All measures taken within a half hour
Ozeri scale – 43.3%
Omron handheld – 39.5%
Accumeasure single point – 30.7 (self measured)
Jackson/Pollock 4 points – 30.83 (my son helped measure)
I am a pretty big guy 5’9″ and 278 lbs. I’m very active but still have a lot of fat. I’ve found that the Omron will fluctuate almost 3% in a single 24 hour period. The Ozeri is pretty much worthless to me – It supposedly measures water, fat, muscle, and bone weight. It shows me as having less than 4 lbs of bone – not likely.
The accumeasure and Jackson Pollock are fairly consistent with each other and from day to day. I don’t know if they are accurate about actual percentage but they are more reliable for historical comparison of myself over time. The electronic devices only frustrate me with such wild readings.
@brotherchris – thanks for sharing those results. That’s very helpful. I prefer measuring fat directly with calipers as long as the measurements can be consistent with successive trials.