If you want to know what works for calculating body fat percentage and what doesn’t, then you want to read this article.
- Body fat percentage is the percentage of your body weight that’s fat.
- A healthy body fat percentage for men is 8 to 17% body fat, and for women it’s 15 to 24%.
- The best way to measure and track your body fat percentage is to weigh yourself daily, and take caliper and waist measurements and progress pictures weekly.
Just want a calculator to help you calculate your body fat percentage?
Here you go:
Want to learn more about the art and science of measuring your body fat percentage? Keep reading. 🙂
The first time I tried to formally calculate my body fat percentage, I was confused. Here’s how I looked:
I know that bodybuilders compete at 4 to 5% body fat, so I figured I was around 7 to 8%?
What would you guess my “score” was? Would you believe …
That’s the number my friend and I were getting with our “bodybuilder approved” multiple-point caliper test (that we did several times to confirm).
I weighed about 184 pounds in that shot, so according to these calipers, I was still carrying about 20 pounds of fat.
To put that in perspective, here’s what just one pound of fat looks like in terms of volume:
You couldn’t pinch more than skin anywhere on my body, so where was all this phantom fat hiding, exactly?
And considering what it took to get this lean, if this really was 11% body fat, I guess 7% is just impossible?
Well, quandary in hand, I set out to find an answer. And in this article, I want to share what I’ve learned, including …
- What “body fat percentage” means.
- The pros and cons of popular ways of calculating body fat percentage.
- How to determine your body fat percentage with a fair amount of accuracy.
- Why obsessing over body fat percentage is counterproductive (and what to do instead).
- And more.
Let’s get started.
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What Is Body Fat Percentage?
Your body fat percentage is the percentage of your body weight that’s fat.
For example, if you weigh 150 pounds and have 15 pounds of fat, your body fat percentage is 10% (15 / 150).
This means that your body fat percentage is a moving target, changing when you gain or lose fat, of course, but it also when you gain or lose muscle.
For example, if you used proper diet and weightlifting to increase your weight from 150 to 170 pounds with just 5 pounds of additional fat gain, your new body fat percentage would be about 12% (20 / 170).
If you then stopped lifting for a year and lost, let’s say, 10 pounds of muscle but no fat, your body fat percentage would still be about 12% (20 / 160).
So, your body fat percentage ebbs and flows as you change your body composition.
Why Body Fat Percentage Is More Important Than BMI
Many people mix up body fat percentage and BMI, but they’re completely different.
BMI stands for “body mass index,” and it’s a numeric expression of the relationship between your height and weight.
You calculate your BMI by dividing your weight in kilograms by your height in meters squared. For example, here’s my BMI in the picture I shared earlier:
- 184 (pounds) x 0.45 = 82.8 (kilograms)
- 74 (inches) x 0.025 = 1.85 (meters)
- 1.85 x 1.85 = 3.4225
- 82.8 / 3.4225 = 24.2 (BMI)
And here’s how BMI values are correlated with body weight status:
- Underweight = <18.5
- Normal weight = 18.5 to 24.9
- Overweight = 25 to 29.9
- Obesity = BMI of 30 or greater
As you can see, according to the BMI measurement, I was borderline overweight. Silly, right?
That’s the rub with BMI: it’s useful for analyzing broad populations but not so useful for assessing individual fitness.
Body fat percentage is much better for this purpose.
Can You Determine Your Body Fat Percentage Based on BMI?
BMI is solely based on your height and weight, and it doesn’t take into account how much of that weight is fat versus muscle.
This means that BMI can be high for very different reasons. On the one hand, it can be high because, like me, you have a relatively high amount of muscle mass and low amount of body fat…or because the opposite is the case—a low or even average amount of muscle mass and high amount of body fat.
No matter how you slice it, BMI simply isn’t a good way to estimate your body fat percentage.
What’s a Healthy Body Fat Percentage for Men and Women?
As much as it’s generally despised, body fat is much more than a layer of ugly, unwanted, greasy flesh.
It plays many vital roles in the body, including protecting organs from damage, maintaining body temperature, producing hormones and other chemicals, and much more. That’s why there’s a limit to how lean you can get before your health declines. What’s that limit, though?
Well, here are two body fat charts that show how various body fat percentages play out for both men and women:
(In case you’re wondering, the additional fat that women carry in their breasts, hips, thighs, and butt accounts for their generally higher body fat ranges.)
The reason for this is because once you get this lean, all that remains is “essential” body fat stored in nerve cells, brain tissue, joints, and the pads of your hands and palms of your feet, and around major organs like the heart and intestines, and thus is required to stay alive.
Once you hit this essential body fat range, your life is literally on the line. Keep losing fat and your heart can stop or you can wind up in a coma, which your body protects itself against by beginning to break down muscle tissue and then internal organs for energy instead of relying heavily on body fat. This is why studies show that people who die of starvation still have most of their essential body fat.
You might be scratching your head at this point because because of some of the sweet body fat brags you’ve heard around the gym. For instance, I’ve heard guys say they got down to 2% body fat for competitions, and I’ve heard girls claiming 5 or 6%. As you now know, this is physiologically impossible.
How can these people be so off in their body fat estimations?
Usually it’s just willful ignorance, but sometimes it’s because the methods they use to measure their body fat percentage are wildly inaccurate (and especially in people who are already lean—more on this in a moment).
For reference’s sake, here’s what 4% body fat actually looks like in a man:
And here’s what a real 10% looks like in a woman:
Unless you’re a competitive bodybuilder and know exactly what you’re doing and why, don’t ever try to get this lean. Your hormones can go haywire, your organs can fail, and even when you avoid disaster, the road back to normality can be quite long and bumpy.
Fortunately, you’re probably like most people and would never want to get that lean. Instead, you probably want to be in the lower end of the athletic range—around 7 to 10% for men and 13 to 20% for women—which is what most people would consider “ripped” or “shredded.”
Here’s what this looks like for a man:
And here’s what it looks like for a woman:
(In case you’re wondering, I’m sharing mostly pictures of elite athletes because there’s a lot of high quality research on them. This is why, for example, we know that the top level male athletes in many sports are usually around 6 to 10% body fat, and the females are generally around 13 to 20%.)
Anyone can get to this look with proper dieting and exercise, but it’s very tough to maintain for long periods of time. If you want to maintain this look, it requires strict control of calorie intake, which can be particularly hard if you’re fighting against your body’s natural set point, as well as a rigorous and regular exercise routine.
Furthermore, although you can be healthy at these lower levels of body fat, you don’t need to be that lean to be healthy (and below a certain point, getting leaner doesn’t improve your health).
Specifically, the health benefits of fat loss drop off around 15% body fat in men, and 25% in women.
In other words, reducing your body fat percentage below the “fit” range is more about vanity and feeling better about how you look rather than improving your health (which is a perfectly valid reason to do it, in my opinion).
What does this “fit” range of about 15/25% body fat (men/women) look like exactly?
Well, here’s ~15% in men:
And ~25% in women:
As you can see, this is where you look healthy and athletic but lack the definition and razzle-dazzle of the lower body fat levels.
Once your body fat levels rise above the “fit” range, you begin to look decidedly “overweight.” I generally recommend that people don’t exceed this range because it can get unhealthy, it slows down muscle growth, and it makes subsequent efforts to get lean long and grueling.
Here’s what I’m talking about in men:
And here’s women:
What’s the Lowest Body Fat Percentage You Can Maintain?
Here’s another picture of me at my leanest (probably around 7% body fat):
I liked being this shredded because, uh, reasons, and tried to maintain it, but after a couple of months I ran into a few problems:
1. I wasn’t enjoying my workouts.
My strength was down on my big lifts by about 5% by the end of the cut that got me here, and it wasn’t coming back, and I didn’t have as much energy and drive in my training as I was used to.
2. I had to be OCD about my food intake.
Because I was only exercising 5 to 6 hours per week, I had to pay close attention to everything I ate and couldn’t do much in the way of cheating, and especially not with high-fat foods, so that killed the excitement of going to restaurants, and it made social gatherings less enjoyable.
3. I couldn’t eat as much as I wanted to.
I was getting hungry throughout the day, which is very unusual for me, and could feel that my body wanted more food than it was getting.
So, I increased my calorie intake (mostly in the form of carbs), and gradually let my body fat percentage rise to a more sustainable, healthy, and enjoyable range.
And here’s a picture of me now (around 10% body fat):
I’m stronger, I have more energy in my workouts and in general, I can be more relaxed about my diet, and I can eat significantly more calories every day (despite only a small increase in body fat).
In other words, if I want to enjoy my life, the lowest body fat percentage I can maintain on my current exercise schedule is around 9%. Once I go lower, the problems begin. Why?
This phenomenon can be explained with what’s known as “set point theory,” which states that the body uses hormones, hunger, behavior changes, and other physiological mechanisms to “defend” a certain range of body weight (and body fat in particular).
A simple way to think of this is as a “thermostat” or “cruise control” system for body weight and fat levels. Whatever numbers are set are what your body strives to maintain.
While a more accurate term would be “settling point” because “set” implies fixed and unchanging, and fortunately this isn’t the case, the basic premise of the body weight set point theory is sound.
Your body likes to maintain a certain amount of body fat to maintain proper hormonal, metabolic, and reproductive function, and strength and cognition, and it fights back when you try to go lower than this amount. Hunger rises, anabolic hormones like testosterone drop, libido tanks, and recovery and muscle and strength gain grinds to a halt.
Everyone’s natural “settling point” is slightly different based on their genetics, activity levels, food choices, etc, but everyone experiences these side effects when they get lean enough. For men, this point tends to be about 8 to 10% body fat, and for women it tends to be about 18 to 20% body fat.
Anecdotally speaking, after having worked with thousands of men and women, I’ve found that the majority are happiest with how they look and feel when they’re in the upper end of the “athletic” range, or around 8 to 12% body fat for men and 18 to 22% body fat for women.
This is lean enough to have abs and decent muscle definition and vascularity, but not so lean that every day feels like an uphill battle against the lethargy and irritability that often accompany lower body fat levels. Most people can also maintain this level of leanness without meticulously counting calories, following a rigid meal plan, or doing excessive amounts of exercise.
Personally, I like to hang out around 9 to 10% body fat for most of the year because it’s easy to maintain on my normal workout schedule, and it keeps me within striking distance of lower body fat levels if I feel like getting really lean.
How to Calculate Your Body Fat Percentage
There are quite a few ways of calculating your body fat percentage and you can get quite a few different results.
In my case, the multiple-point caliper test said 11%, but the handheld device (which we’ll talk about soon) said 8%, and a different single-point caliper said 6%.
Body Composition Scales and Handheld Devices
These instruments use a method called bioelectrical impedance analysis (BIA), which involves measuring your body’s resistance to a light electrical current.
Muscle conducts electricity well because it’s over 70% water and fat doesn’t because it holds much less water. Thus, the more resistant the body is to an electrical current, the fatter it must be.
That sounds reasonable enough but there are serious problems with BIA …
Electricity will take the path of least resistance.
As the current passes through your body, it will avoid fat stores for tissues that are easier to traverse. (Internal tissues will be chosen over subcutaneous fat, for example.)
Making matters worse is the fact that two-electrode devices (like most scales and handhelds) skip entire portions of your body.
Foot-to-foot scales miss your entire torso and hand-to-hand devices miss the lower half of your body.
As you can imagine, this corrupts the results.
Another problem with BIA is it uses mathematical equations to turn raw readings into body fat percentages and these equations can be fundamentally flawed.
You see, when a company develops a BIA device, they calibrate it using another imperfect method of measuring body fatness like hydrostatic weighing.
There are several steps involved:
- Measuring the body fat of a large group of people with the “control” method.
- Measuring them again with the BIA device.
- Comparing the readings.
- Developing an equation to predict BIA results based on height, weight, gender, and other variables.
This could work if the control method’s readings were accurate, but they’re often not.
That is, many companies are calibrating their BIA devices to conform to incorrect calculations of body fat percentage.
Hyrdrostatic weighing is most frequently used for BIA benchmarking, and studies show it can be off by as much as 6% for various reasons relating to ethnicity, body weight, hydration status, and more.
If 6% off doesn’t sound too bad to you, realize that when I’m talking error rates in this article, I’m talking in absolute terms, not relative.
In other words, someone at 10% body fat may register at anywhere from 6 to 16% with hydrostatic weighing.
Body conditions can dramatically influence readings.
Test your body fat with BIA when you’re dehydrated and you’ll read abnormally high due to lower conductivity.
These are some of the reasons why scientists have said that consumer-level BIA devices aren’t suitable for accurately estimating body fat percentage.
What about using one for tracking changes to your body fat over time, though?
If BIA were at least consistently inaccurate, that would work, right?
Sure … but it’s just too all over the place even for that.
Readings are inconsistently inaccurate because they’re influenced by too many things that you can’t easily control, making these machines more or less useless.
Body Fat Calipers and Skinfold Testing
Skinfold testing uses calipers to measure the thickness of your skin at various points on your body.
The measurements are added together and fed through a couple of equations that ultimately give you a body fat percentage.
You probably already see where this can go wrong.
Namely, if you pinch too little skin, you’ll read lower than you are. Too much and you’ll read higher.
Unfortunately pinching perfectly isn’t a guarantee of accuracy, though, due to bad equations.
For example, in one study a team of scientists at the VA Medical Center in Durham North Carolina took skinfold measurements of 681 healthy men and women. As a control, they also measured everyone’s body fat percentage using a far more accurate technique known as the 4-compartment model (more on this in a moment).
They found that the skinfold measurements were about as accurate as the 4-compartment model for measuring the average body fat percentage of the entire group. When it came to individuals, though, the skinfold measurements were wildly inaccurate for many of the participants. In many cases, skinfold measurements either over- or underestimated body fat percentage by as much as 10 to 15% (absolute!).
That is, a guy at 20% body fat could get a reading of 5% body fat (shredded) or 35% body fat (obese) using skinfold measurements.
The upside to skinfold testing is some methods are more accurate than others and lend themselves well to tracking changes to body fat levels over time.
We’ll talk more about this soon.
Pictures and the Mirror
This is the simplest and most obvious way to guesstimate your body fat percentage.
Most people around certain body fat percentages look similar … if they have similar amounts of muscle.
If they don’t, though, then the same body fat percentage can look quite different on two different physiques.
For example, a 160-pound guy at 10% body fat has 16 pounds of fat, and a 190-pound guy at 10% has only 3 pounds more fat but quite a bit more muscle, giving him a dramatically different look.
Here’s a good visual of this:
Both guys are around 10% body fat, but the one on the left has a good 20 to 25 pounds of muscle on his skinny fat neighbor.
Now, if you’re still reading this, there’s a good chance you’re into working out and have more muscle than the average guy or gal.
If that’s the case, then the following images will help you estimate your approximate body fat percentage.
The coveted “six pack” emerges around 10% body fat, ab/core vascularity becomes visible around 8%, and the “carved out of stone” look requires about 6% or less.
As you can see, 10% in men is relatively lean but in women, it’s competition lean.
Dual-Energy X-Ray Absorptiometry (DXA)
DXA (sometimes called DEXA) uses a full-body X-ray to help calculate your body fat percentage.
The scientific basis of the method is fat and fat-free mass absorb X-ray energy differently, which allows each element to be isolated and measured.
You might expect it to be highly accurate, and in fact many people believe DXA readings are unerring, but research shows otherwise.
They can be just as inaccurate as any other method we’ve discussed so far.
This helps explain why many bodybuilders in contest shape have been perplexed by DXA readings of anywhere from 6 to 10%.
There are several reasons for DXA’s fallibility:
- Results can differ between machines, both from the same and different manufacturers.
- Accuracy is affected by gender, body size, body fatness, and even disease state.
- Different machines use different algorithms to interpret the raw data from body scans, and some are better than others.
- The type of X-ray used (fan or pencil beam) influences the accuracy of the test.
- How hydrated you are during the scan can greatly affect the results.
So, as with other methods like BIA and skinfold testing, DXA scan can give an accurate calculation of your body fat percentage, but it can also be quite off.
The Bod Pod is a machine that works similarly to hydrostatic weighing, but uses air instead of water.
You sit in a sealed chamber and sensors measure the amount of air your body displaces. Mathematical formulas are then used to translate the readings into body composition statistics.
We already know how inaccurate hydrostatic weighing can be, and unfortunately, the Bod Pod seems to be even worse.
This helped explain for me some of the rather shocking Bod Pod readings I’ve seen working with others.
I’ve come across dozens of people in my travels whose Bod Pod measurements were easily double their actual body fat percentages (you don’t need more than eyeballs to know that a guy is around 10%, not 20%).
The Most Accurate Way to Calculate Body Fat Percentage
If you’ve been paying attention, you’ve probably wondered how scientists were able to determine the error rates of various testing methods.
What were they comparing BIA, DXA, Bod Pod, hydrostatic weighing, and skinfold results against to check accuracy?
What’s the true “gold standard” of body fat calculation?
Well, it’s a method known as a “4-compartment analysis,” which involves using several testing methods to, piece by piece, separate body weight into four categories:
- Muscle tissue
- Fat mass
Hydrostatic weighing is used to measure body density, deuterium dilution is used to measure total body water, and DXA is used to measure total bone mass.
The data collected from each of these tests is then manipulated with various equations and the result is a consistently accurate measurement of body fat percentage.
This is nice to know but of not real use to us because, well, it requires a team of scientists.
Fortunately, though, there is a method of calculating and tracking body fat percentage that I feel is accurate and consistent enough to warrant our attention.
How I Measure and Track My Body Fat Percentage
I track changes in my body fat percentage with calipers, a scale, a measuring tape, and the mirror.
Here’s how I do it …
I weigh myself daily and calculate an average every 7 to 10 days.
Your weight can fluctuate from day to day due to things you can’t see like water retention, glycogen storage, and bowel movements.
This is why you don’t want to put too much stock in daily weight measurements.
Weekly weight averages are much more useful because they give you a truer picture of what’s happening.
If your 7- or 10-day average is going up, you’re gaining weight. If it’s going down, you’re losing weight.
So, weigh yourself every day first thing in the morning after the bathroom and before food or water.
Record these daily weights and take an average every 7 to 10 days (sum the daily weights and divide by the number of days).
Watch those averages and you won’t need to fret over temporary movements up or down.
I take weekly caliper measurements.
Generally speaking, if your skin is getting thicker over time, you’re gaining fat. If it’s getting thinner, you’re losing fat.
This is why caliper readings can be very useful, despite not being inherently reliable for extrapolating body fat percentage.
I’ve tried many calipers and skinfold testing methods, and here’s what I’ve found best:
There are two reasons I like this caliper:
- It’s a one-site testing method, which means there are less ways to screw it up.
- It’s surprisingly accurate.
I’ve worked with hundreds of people using this caliper and rarely see flagrant misestimations (it seems to be accurate to within 1 to 2%).
Here’s how to use it:
I take weekly waist measurements.
The size of your waist (measured at the navel) is a reliable indicator of fat gain or loss.
An expanding waist indicates fat gain and a shrinking one fat loss, which is why it’s another good measurement to keep an eye on (and all you need is a simple measuring tape.)
I take weekly pictures.
If you’re like most of us gymgoers, the point of all of this is what you see in the mirror.
And when you look at yourself every day, you can get discouraged because you’re not seeing the gradual improvements.
Taking weekly front, side, and back pictures in good front-on lighting helps greatly with seeing your progress and staying motivated.
Frequently Asked Questions About Body Fat Percentage
What is the ideal body fat percentage for a woman or a man?
There is no “ideal” body fat percentage for health, fitness, and aesthetics.
Instead, it’s better to think of ideal ranges of body fat based on your goals.
If your goal is to look athletic, stay healthy, and avoid disease, then you should aim for a body fat percentage of around 20 to 25% for women and 10 to 15% for men. Getting leaner than that isn’t necessary for health purposes.
If your goal is to stay impressively lean and you’re willing to be very strict about your diet, then you should aim for a body fat percentage of 16 to 18% (women) or 6 to 8% (men).
This isn’t generally sustainable long term, and I don’t recommend you try to maintain this level of leanness year round, but it’s doable for short periods of time.
How much body fat do you have to have to see your abs?
Men usually need to be below 10% body fat to see clear separation between their abdominal muscles, and women usually need to be below 20%.
You can use the chart below to learn how long it will take to get abs:
You can learn more about how lean you have to get to see your abs in this article:
What is the average body fat percentage?
In the United States, the average body fat percentage for men is 28%, and the average body fat percentage for women is 40%.
In other words, most Americans have about twice as much body fat as they should in order to look athletic and stay healthy and disease free.
The Bottom Line on Calculating Body Fat Percentage
Your body fat percentage is simply the percentage of your body weight that’s fat.
It’s a better measurement of your overall health, fitness, and body composition than BMI, and it’s also useful for setting weight loss goals.
A healthy body fat percentage for men is around 8 to 16% body fat, and a healthy body fat percentage for women is around 16 to 24% body fat.
I’ve found that most are happiest with how they look and feel when they’re in the middle of this range—around 8 to 12% body fat for men 18 to 22% body fat for women.
Trying to stay leaner than this is usually more trouble than it’s worth.
Many people love to brag about their (supposed) body fat levels, but the only way to know your body fat percentage with absolute certainty is to remove all the fat from your body and weigh it.
And I doubt even the most narcissistic of the bunch are going to volunteer for that.
So with autopsy off the table and 4-compartment analysis out of reach for most of us, here’s the bottom line:
Body fat calculations themselves aren’t as important as how they’re changing over time.
This is why I don’t bother with inconvenient and expensive testing methods like DXA or the Bod Pod.
You may or may not get an accurate reading, so why bother?
Instead, you can just use your weight, skinfold results, waist measurement, and pictures, and know exactly what’s happening with your body.
Ready to start changing your body today? Check out this article on how to lose weight as fast and efficiently as possible: