How to Estimate Your Body Fat Percentage (BF %)

What is the measurement of body fat percentage?

Put simply, the measure of body fat percentage is assessing what portion of your body is made up of fat. The remaining weight spread between organs, water, muscle tissues, bones, etc.

If you weigh 200 pounds, and 20 pounds of that is fat, then your body fat percentage is 10%. 30 pounds of fat would put it at 15%, 40 pounds at 20%, and so forth. The rest we refer to as your lean mass.

If you gain or lose only fat, your body fat percentage goes up or down accordingly. But it can also go up without gaining fat, and down without losing fat.

How is that possible? By subtracting or adding muscle.

Let’s say you’re fairly muscular and weigh 190 pounds with about 25 pounds of that being fat. That puts you around 13% body fat (25/190). If you stopped lifting and lost 20 pounds of muscle over the course of a year, without losing any fat, you now weigh 170 pounds with the same 25 pounds of fat. Your new body fat percentage is about 15% (25/170).

On the flip side, let’s say you weigh 170 pounds and are carrying 20 pounds of fat. Your body fat percentage is around 12% (20/170). If you gain 10 pounds and little-to-no-fat, you now weigh 180 pounds with the same 20 pounds of fat, and your body fat has now dropped to 11% (20/180).

What are the methods of measuring body fat percentage?

There are quite a few methods of measuring body fat; the most common methods are the following (in order of probable accuracy)

  1. Dual energy X-ray absorptiometry (DEXA Scan)
  2. Hydrostatic Testing (Underwater Density Test)
  3. Air Displacement Plethysmograph (BOD POD)
  4. SKULPT Device – Great way to measure and track progress.
  5. Skinfold Measurement (Skin Pinch with Calipers – only recommended when done by a professional)
  7. Bioelectrical impedance analysis (Handheld/Scale device)
  8. Height and circumference methods (Measurement Collections)

As mentioned above, a great and somewhat reliable (for most body shapes) ways to estimate BF% and review progress over time, is the NAVY FAT method, that is estimated with just a tape measure.

This is an easy and great way to estimate both a starting point and subsequent progress over time.

Try the Navy Fat method HERE.

When we look at the error factors of these methods, we see pictures can be used as much as anything else.Of all these tests, it is a general consensus the DEXA scan provides the most accurate results you can achieve beyond doing an autopsy. Knowing the exact body fat percentage while living is extremely difficult.

There are many cons to the different types of measurement. Water is usually the leading deceiver of body fat readings in all methods.

Learn more HERE.

Do we need to know our body fat percentage?

Technically, there is no need to know our body fat percentage. While our body fat percentage can provide insights into our health status, simply knowing doesn’t do much to change things. Knowing merely provides amusement, motivation, or a harsh dose of reality.

What is the minimum body fat percentage for human beings?

There is currently no definitive answer for what is essential body fat. Looking at research though we assume a range of 5% for men and 12% for women is landing in the essential range. For hormonal and reproductive reasons women need to store a higher level of body fat than men. It is thought that 15% is the lowest range a woman should maintain. There is some argument about this, but technically the data isn’t there to conclude if it is body fat or lifestyle/training habits that cause problems. In my personal opinion, I think women should tread lightly trying to maintain body fat levels below 15%.

In recent years body fat percentage is being considered a better and more popular way to view health markers of individuals over the traditional, and largely inaccurate, BMI index.

Distribution – Body fat distributes itself a little bit differently on everyone’s body. Most men may carry extra weight on their stomach or love handles, usually referred to as a spare tire. Some men will have leaner arms  or legs with a big belly while others will be more evenly distributed. Women seem to have the biggest difference in distribution. While the many carry extra weight on their thighs and upper arms with a leaner mid section, some women will be the opposite and carry more in the middle than on their limbs. Photos for both try to focus on the mid section (+thighs for women) where these differences are most apparent.

Build – Like different distribution of fat, most of us have different statures and will look different even at the same bf%. The amount of lean muscle that you have plays a huge role in determining how you will look. Someone with more muscle can look as though they have a higher body fat percentage when muscle separation isn’t clear. I give a couple of examples of this below. We’ve tried to pick images of fairly average builds with some more and less trained individuals as well for comparison.

Age – As you age you tend to store more fat in amongst your organs (visceral fat), and in the muscle itself (intramuscular fat). This means someone who is in their early twenties who has the same amount of fat under the skin (subcutaneous fat) as someone in their fifties, will be at a slightly lower body fat percentage. Most skinfold or other external measure formulas take this into account while the direct measurements like DEXA may be able to even differentiate the types. Below, most pictures are in the 25-35 age range, you may need to adjust slightly depending on age.

Muscle Definition and Striations – Muscle definition become more pronounced as body fat becomes lower, showing clear separation between the muscle groups. This will depend on level of training and how much muscle you actually have. With even lower body fat you start to see striations in the muscle itself that appears as the bundles of fibers can be seen.

Vascularity – Looking vascular is up to several factors. Genetics is first dictating how big and where, the second is a combination of musculature to push them out and low body fat so they’re not covered up. As you lower your body fat percentage, you’ll begin to see veins appear in different areas, usually starting on in your forearms.

Does everyone look-alike at the same body fat percentage?

No, not at all. Body fat percentage isn’t an indicator of your amount of lean body mass.  The amount of muscle your body has is going to make a significant difference in your overall look. What is the right look? This is up to personal preference and program design. This post isn’t about judgment, but more so a definition of the difference between the two.

Take these two males in the picture below. Both are roughly at 10% body fat.  As you can see, there is a noticeable difference in their looks and muscle composition. Again, this isn’t about judging, but simply stating a noticeable physical difference. The man on the left has a legitimate 15 or more pounds of muscle than the guy on the right.

The same is true for these females below. The first is a fitness competitor and the later is a fashion model. You may or may not like one or the others appearance, but that isn’t the point of the comparison. The point is both are roughly 15% body with varying levels of water depletion. As you can see, there is quite a stark difference between the two.

There are also other variables and factors to take into consideration when looking at body composition. One of the main factors is carbohydrate and water manipulation. Water manipulation or advanced super-compensation techniques can have dramatic differences on your appearance. It is often done by bodybuilders and figure competitors.


As you can see body fat percentages range and methods for measurement vary. You can also see training will have the greatest effect on what you look like at various body fat percentages.

Why measure body fat percentage at all?

So after all of that, if we look different at the same body fat percent percentage, and if it doesn’t really matter what’s the purpose?

Lean Mass – For KETOGAIN’s purposes, we want to know your lean mass. This is the sum of everything that isn’t fat in your body. In most cases, the more lean mass you have, the better for overall health. Lean mass helps calculate your base metabolic rate and other variables using our calculator, we’re not feeding your fat, we’re feeding the machine underneath.

Health – While body fat percentage alone doesn’t really tell you anything, it is one more health marker to have in your toolkit. Overall health can be correlated with having a body fat percentage in a normal range with more accuracy than BMI. Many diseases are correlated with too much visceral fat or body fat accumulation in general.

Tracking – Statisticians or number junkies aside, for anyone starting a training program or just looking to lose weight, you will usually do much better if you track some variables. By making some measurements and tracking changes over time you can see the data trend one way or another. One important place for this is weight loss. You don’t want to lose muscle or lean mass if you don’t have to. By tracking your body fat percentage you can calculate any changes in lean body mass, you want to see lean mass stay relatively stable or trend up rather than down. If you’re losing lean mass you might need to re-evaluate your macros or approach. Equally as important when you’re trying to build, you can see how much lean mass is being put on as there is no direct way to measure it as well as see how much of the weight change is fat mass.

Body Fat Comparison: Male

Various Body Fat % Levels of MalesVarious Body Fat % Levels of Males

Various Body Fat % Levels of Males


In this range you will find competing bodybuilders and the emaciated. When prepping for contests you can find body builders in this range temporarily. Nearly all external veins may be visible on each muscle, very distinct separation, and visible striations in nearly all muscle groups including the glutes, the last bastion of body fat. At barely more than required to protect your organs to function (roughly 2%), you’ll have almost no subcutaneous fat and only some visceral left.


This body fat percentage is not sustainable for most men. Around this level, all of your muscles will show noticeable definition and clear vascularity in most muscles. There will be a pretty clear distinction between each muscle. Even the abs will show vascularity at the lower end of this spectrum.


This is the range that most men want to be at for a classical “beach body” look. There will be separation between muscles, but not in every muscle. Veins will mostly only show on the arms, and sometimes the legs with some striations visible in forearms or possibly shoulders, Lower abs may sometimes still be hidden by a little pouch of fat.


This is more of a lean look, with less muscle striations and vascularity. The definition on muscles goes down and there is not a clear separation between them. Most vascularity is gone, but some can still be seen on the arms. Most athletes fall into this category or lower and can be maintained by most people with relative ease.


This is the most common range for “young adult” men to be in, where the separation between muscles begins to become nonexistent. There are almost no striations or vascularity in any muscle groups. Typically there will be a little bit of fat on the stomach, but it will not be rounded. A male of 5’10” – 5’12” who weighs 180 – 185 lbs will probably be at 20 to 22% BF.


Any range above this is considered obese in most men. The waist size starts to increase and the stomach shows visible rounding. There may still be little neck fat, but most men gain weight in their stomachs first. There’s no separation of muscles and veins typically don’t show. A male of 5’10” will probably have a waist size of over +35 inches.


The fat starts to distribute around the body and the waist will look larger relative to the hips. The stomach will be noticeably more round and chin fat will start to form. Very probalbly there is no visible muslce separation.


The stomach will start to gain more and more fat around it, and waist size usually is over +40 inches. The stomach will have clear protrusion and hang (the classic beer gut).


Everyday activities begin to be very difficult to perform, and this is where the body fat level is approaching morbidly obese. The stomach will continue to grow and the chest will gain more fat as well as more fat accumulation on the limbs. Waist size will likely approach +45 inches for a 5’10” man.

Body Fat Comparison: Female

Women usually look leaner than men at higher body fat percentages. This is mainly because of the body fat women naturally hold in their breasts, butt, and hips.

Various Body Fat % Levels of FemalesVarious Body Fat % Levels of Females

Various Body Fat % Levels of Females


Women have more fat in breast tissue, waist, thighs and surrounding the organs. The essential body fat for a woman is 8%, while for a man is only 2%. This is the range you will usually see bodybuilders in, and is not considered healthy long termt. Muscles are clearly defined and separated, and vascularity is noticeable all over the body. The less vascularity, the further away from 10% body fat you deviate.


The hips, thighs, and butt usually have less shape because of the lack of body fat. Many bikini, fitness models, and some athletes are usually within this range. Vascularity is usually only in the arms and some in the legs, and there is still separation between muscles, with clear definition. Still considered low for women it may not be very sustainable in the long run.


The separation between muscles, as well as the definition in the muscles becomes less apparent in the limbs while abs should still retain some definition. This is the range that most female athletes fall in, and is considered as highly fit and more sustainable.


This is the range that most women fall into, as it is not too slim or overweight while being maintainable. Curves begin to form in the hips as there is more body fat around the thighs and butt. A 5’4” – 5’6”  woman of 130 – 135 lbs will probably be at 25 to 27% Body Fat.


As women begin to gain weight, instead of it going to their stomach, it will begin to show around the hips, thighs, and butt. In this range, the butt and thighs will likely be more rounded and pronounced.


At this level of body fat, the face and neck will begin to gain some more visible fat. The stomach may also start to gain fat and be protruding a little. Usually the waist is over +32 inches and hips over +40 in this range. 


The thighs and hips will continue to have fat funneled into them, and grow very large. Visible hang of the stomach at this point. At this level of body fat, the waist is typically over +35 inches, hips over +42 inches, and thighs over +25 inches.


The waist can be over +37 inches while hip circumference may reach +45 inches and become more noticeaby wider than the shoulders. Typically, the skin will begin to lose its smoothness and often show dimpling on it.


Due to the fat cell structure in women much of the skin will show visible cellulite dimpling. Both waist and hips will be wider than the shoulders. Waist will probaly measure over +40 inches, hips +45 inches and thighs over +30 inches, for a 5’4” woman who weights +200 lbs.