The Ectomorph’s Guide to Body Fat Percentage

Did you know that being skinny means you can’t use the normal way of measuring your body fat percentage?

Or that being just a little bit too skinny-fat might sabotage your ability to build muscle leanly?

Or that most body fat percentage charts are ruined by a fatal flaw?

In this article we cover why your body fat percentage matters even as an ectomorph, how to measure it properly, and then we’ll run through some real-life examples (with pictures) so that you’ll know exactly what to do next.

But first, let me show you just how ridiculous this can be for skinny guys.

Let’s take a totally average guy in this study. He goes to get a DEXA scan, and he’s told that he has a body fat percentage of 20%. Then he goes to sit in the BodPod, which puts him at 22%. A bit of a discrepancy, but he can be reasonably confident that he’s between 20–22%. Moreover, both of those body fat percentages have the same implication for his health and appearance: he’s a decently healthy guy who looks a bit out of shape.

The overweight guy goes in next. DEXA puts him at 34%. BodPod puts him at 32%. Now it’s DEXA that’s estimating high, but the discrepancy is still just 2%. Again, not a big difference at all. He’s overweight either way.

Now you walk in. DEXA puts you at 9%. Amazing! Not only are you lean enough to bulk aggressively, but you’re also leaner than most professional athletes. Next, you get your BodPod done. They tell you that you’re 16% body fat…

Huh? 16% is a high enough body fat percentage that you shouldn’t even be bulking at all yet. You should be cutting.

You’ve spent a few hundred dollars and an entire day getting two of the most accurate body fat percentage tests in the world, and you can’t even tell if you should start bulking or not. For guys who are underweight, DEXA and BodPod can be off by up to 13%. Totally useless.

So what should you do?

…and wait a second—why shouldn’t you bulk if you’re 16% body fat?

Why 15% body fat marks a turning point

When you’re under 10% body fat, your deflated fat cells are hungry. It’s very hard to bulk leanly, and if you focus on trying to stay at a very low body fat percentage, you’re going to build muscle very slowly. If you’re lucky, you’ll gain a pound every month, and even then, only half of it will be muscle. This gets more and more extreme as your body fat percentage gets lower, so building muscle at 9% is a lot easier than building muscle at 5%.

For example, when a bodybuilder steps off stage and gets back to eating a regular amount, he’ll often gain 10–20 pounds of pure fat. His body needs fat far more than it needs muscle at this point. Then when he gets closer to 10% body fat, he can start bulking properly again. 

Also keep in mind that if you cut down to under 10%, it tends to make your face look worse. Muscles look good when you’re lean, but you don’t have many muscles on your face, so at a low body fat percentage your face starts to look bony.

When you’re over 15% body fat, your inflated muscle cells start to interfere with your overall insulin sensitivity. Even with a great weightlifting routine, you won’t be able to get your muscle fibres quite as insulin sensitive. And even a good muscle-building diet won’t be able to spark quite as much muscle-protein synthesis. This gets worse and worse as your body fat percentage gets higher and higher, so bulking at 17% is a lot easier than bulking at 30%.

This is why so many skinny-fat guys are unable to bulk leanly. When they gain weight, it seems to be mostly fat. So they cut away the fat until they’re back down to 20%, and then they try bulking up again, and again they just get fatter. So they give up, thinking that their genetics suck.

Their genetics don’t suck, they’re just not lean enough to bulk properly. They should be reducing their body fat percentage a little bit before trying to bulk up. Here’s how that works: what to do if you’re tired of being skinny-fat.

Note: being over 15% body fat doesn’t mean you’re fat. The average healthy guy has 20% body fat. It just so happens that when you’re trying to build muscle, it’s better to be on the leaner side of healthy.

When you’re in that golden zone of 10–15% body fat, your fat cells are satiated enough that your insulin sensitivity drops. But they aren’t so full that they start messing with your hormones, either. They’re neutral. So when you start following a good weightlifting program, the insulin sensitivity in your muscle cells will skyrocket. Feed yourself a good muscle-building diet and your muscles fibres will grow, your fat cells will not.

For example, here’s Taylor gaining 20 pounds while staying between 10–15% body fat.

He’s gaining over a pound per week but he’s hardly gaining any fat. And he’s just doing three workouts per week, each lasting about an hour. No crazy supplements or anything wild, just a solid science-based approach to building muscle.

This is why it’s so important to be able to guesstimate your body fat percentage. It doesn’t matter if you’re a few points off, but you need to know whether your body fat percentage is in the cutting or the bulking range.

Getting under 15% body fat is important visually as well. That’s when you start to look like you’re in good shape. It’s not enough to impress other men, but it’s when you start to look optimally attractive to women.

Some women do prefer chiseled abs, but the research pretty clearly shows that guys are about 99% of the way to optimal attractiveness by the time they get down to 15% body fat. This will not only give you good muscle definition, it will also make your face look lean and healthy.

If you’re over 15%, the quickest way to make yourself more attractive is to trim off a few body fat percentage points. This is true even for skinny guys. If you haven’t built much muscle yet, a good muscle-building program combined with a good cutting diet should allow you to gain a few pounds of muscle even while you lose fat.

Then when you get down to 10–15%, the best way to become more attractive is to focus on building muscle—on bulking up. And since your muscle cells will be more insulin sensitive, you’ll be able to build muscle more leanly (examples coming).

This is all to say that you need a fairly precise way to determine whether you’re under 15% body fat or not.

How to figure out your body fat percentage

We’ve already covered why DEXA scans and BodPods won’t work properly until you’ve already bulked up to a solid weight.

What about bioelectrical impedance analysis (BIA) scales? They’re cheap and convenient—most modern bathroom scales have this feature—but they’re even less accurate than DEXA and BodPod. Again, they’re just not something designed for guys like us. They’re for tracking fat loss in overweight people, not muscle gain in skinny guys.

To give you an example of how bad BIA scales can be, when I was bulking up from 130 to 170 pounds, it told me that my body fat percentage had climbed from 10% up to 20%. This made me sad, but I tried my best to ignore it because my abs looked the same as they always did.

Then something strange happened when I made it up to 185 pounds. It determined that I had an “athletic” body composition, so it switched to using a different algorithm. Instead of 20% body fat, it started saying I was 8.5% body fat.

The Navy’s measuring tape method? Again, this way of measuring body fat percentage used to determine whether a guy is overweight or not. Plus, it reads muscle gain the same as it reads fat gain. Bigger ab and lower back muscles will increase your waist measurement, after all.

How about skin fold calipers? Skin fold calipers require a decent amount of training to use properly. Otherwise, they don’t measure body fat percentage well enough to be that helpful. Still, they’re affordable, you can use them from the comfort of your own home, and they can work well if you can learn to have a skillful hand. Not bad at all, and the best method so far.

That brings us to:

The mirror method. Assuming you already have a mirror, this method is free. It’s also easy. And so long as you’re between 9–15% body fat, it’s actually quite accurate. Unlike the other methods, this is a method that works better the more muscle definition you have. So it works well when you’re thin, and then even better as you gain muscle. 

Moreover, if you’re over 15% body fat, you know you should be cutting anyway. So even when the mirror is inaccurate, it’s still accurate enough to tell you that you should be cutting.

Now, you might be thinking, if you’re cutting, won’t you want to track your body fat percentage to make sure that it’s going down? Actually, no. There are better ways to track your cutting progress.

After all, you should always be following a good weightlifting program while cutting. Obese guys will lose mostly fat when they lose weight, but us naturally skinny guys / ectomorphs are more prone to losing muscle. Since we don’t have any muscle to spare, lifting weights while losing weight is mandatory.

So, since we’re lifting weights anyway, you can just make sure that you aren’t getting weaker. If you’re maintaining or gaining strength, you aren’t losing muscle.

To track how much fat you’re losing, you should weigh yourself each week while cutting. If you aren’t losing 1–2 pounds each week, you need to adjust your calorie deficit. This is how you ensure that you’re steadily losing fat.

So all you need to do while cutting is monitor your strength in the gym, monitor your weight on the scale, and then check how you’re looking in the mirror.

This means that even while cutting, the mirror works pretty well as your primary way of tracking your body fat percentage.

…But in order to use the mirror, you need to know what you look like at different body fat percentages.

In theory, that’s easy enough. You can just look up a photo of people at various body fat percentages. Problem is, most of those comparisons are useless for us ectomorphs.

Here’s a good example of a chart that doesn’t help us:

This Nerd Fitness chart is actually a whole lot better than most, but I chose it because I like Nerd Fitness, and because Steve Kamb makes this same point in his article Everything You Need to Know About Body Fat Percentage: muscle mass has a huge impact on how lean you look.

I couldn’t agree with him more.

Let me show you why.

Here’s GK’s progress over the course of The Bony to Beastly Program. He managed to stay at around 10% body fat the entire way through, but you can see that he started the program with almost no muscle definition, and finished the program looking totally chiseled. This has nothing to do with fat, everything to do with muscle.

So when you get a chart with random variance in muscle mass, it’s impossible to compare body fat percentage. We can see someone’s muscle definition changing, yes, but we have no way to tell whether that’s due to varying degrees of muscle mass or body fat.

There are other problems with this type of  chart:

  • The guys have varying tans. How dark your skin is has a huge impact on how lean you look. That’s why the bodybuilder has such an exaggerated spray tan.
  • Some guys are oiled up. Again, this is a trick used to make guys look leaner.
  • Some guys pumped up their muscles for the photo. Another trick used to bring out vascularity and muscle definition, making guys look leaner.
  • They’re different guys. One guy might have proportionally bigger ab muscles, another might have different body fat storage patterns, some will have different amounts of visceral versus subcutaneous fat.

Moreover, the lighting isn’t the same. For an example of why that matters so much, take a look at Omar’s progress pictures. Like GK, he’s at roughly 10% body fat before and after bulking up.

On the left, he’s at the beach and there’s a lot of ambient lighting. He has abs, but you can only just barely see them. On the right, you can see that he’s gained a ton of size in his chest, traps, shoulders and arms, but is he also leaner? It’s impossible to tell because the lighting is so different.

Generally, overhead lighting will make you look more muscular than ambient lighting. This is why you probably look leaner in your bathroom mirror than you do on the beach (depending on the weather).

It’s even harder for us ectomorphs because so few examples show us skinny guys at varying body fat percentages.

So we’ve got two charts:

  1. An ectomorph who hasn’t bulked up yet.
  2. An ectomorph who’s successfully built a good amount of muscle mass.

And we’ve used illustrations so that we can keep all the variables constant except for body fat.

Here’s how you use the body fat percentage charts:

1) Find a mirror

2) Turn on some flattering overhead lighting (bathrooms work well)

3) Flex your abs and your butt (to rotate your hips into a decent position)

4) Compare your abs and muscle definition to these charts

Here’s what 9–20% body fat looks like on the typical skinny guy:

Here’s what 9–20% body fat looks like on a skinny guy after he’s bulked up:

Real-life body fat percentage examples

Here’s me at 11% as measured by DEXA scan and 10% as measured by BodPod. Note that I’ve bulked up to a bodyweight of 185 here (BMI of 24) so I’m heavy enough for these methods to be fairly accurate.

Here’s what that looks like in video, and with less flattering lighting. As you can see, I look the most like the 12% illustration shown above.

If you want to see what that ideal 10–15% range looks like, here are some examples. I’ll also give some examples of guys bulking at slightly under 10%, or slightly over 15%. In each case, the guy is at a great example of someone who has a perfect body fat percentage for bulking up fairly aggressively.

I’ll give my guesses for what their body fat percentages are both before and after, but keep in mind that the big distinction we’re trying to make is whether they’re lean enough to be bulking.

Here’s a great example of bulking at a very lean body fat percentage. EddiB isn’t even halfway through the program yet, and he’s still going strong, but so far it looks like his body fat percentage is ever-so-slowly climbing up from around 7% as he goes.

What’s great about this is that even if he gains a few more pounds of fat as he continues bulking, he should be able to finish his bulk at an ideally lean body fat percentage.

Here’s a good example of starting at a very lean body fat percentage. JonKyp went from something like 7% up to what looks more like 10%. This is a good example of faces looking great at around 10% body fat.

Here’s Nick starting at what must be around 8% body fat. He’s quite lean after gaining 27 pounds, but I’d guess he’s climbed up to around 11% by the end.

Here’s Albert starting and finishing at around 10%. You can see that his muscle definition goes way up as he bulks, even though he probably gained something like 2.5 pounds of fat to maintain his body fat percentage at 10%.

Lucas gained a bunch of muscle definition as he bulked up, but he’s probably at around 12% both before and after. He’s still at the lower end of the range, so he could just keep right on bulking without any issue.

Here’s Ash gaining a couple percentage points as he bulks, but winding up looking better for it. Looks like around 10% to start, more like 13% at the end.

I’m guessing Patrick was around 11% starting out and around 15% at the end of his 40-pound bulk. At this point, he might want to cut off a few pounds before bulking up more, but he wouldn’t have to—he’s still just barely lean enough at the end.

Here’s JoeBrusk, who started with way more muscle. He was probably at around 15% at the beginning (which is lean enough to look optimally attractive to women), but after some body recomposition, he finished at around 10% (which is lean enough to look impressively badass to other dudes).

John L started out with a good amount of muscle, and at around 14%, I’d guess. He finished at around 15%, I’d say, given that his muscles have about the same amount of definition despite being quite a big larger.

Here’s Hugo starting and around 11% and finishing at around 14%. What’s cool about this one is that he’s gained such an incredible amount of muscle that he’s got way better muscle definition despite being a few body fat percentage points higher.

Here’s a good example of bulking up at the upper limit of that ideal bulking range. I’m thinking Josua is flirting with 16–17%. This has him starting off with little definition, but finishing looking like some sort of professional football player.

I normally use my 130–185lbs bulking transformation, but here’s me at 200lbs cutting down to 180lbs. I started the cut at around 20% body fat and finished at around 10%.

Klaus is a good example of someone who came in at around 20% body fat. He was able to transform his physique by alternating between cutting and bulking, finishing 22 pounds heavier at around 9–10% body fat. What’s so amazing about this is how radically his overall body shape has changed. He’s got a pronounced v-taper by the end of it.

So what now?

If you’re under 15% body fat, the best way to improve your physique is to bulk up, and the good news is that you should be able to build muscle quite quickly. A beginner can gain 1–2 pounds per week, eventually slowing down to gain around 0.5–1 pound per week. You can expect to gain at least 20 pounds in 3–5 months.

If you’re over 15% body fat, the best way to improve your physique is to cut. If you’re still fairly skinny, you should be able to build a decent amount of muscle even while losing weight overall. Over the course of the next 3 months you could expect to lose 20 pounds of fat while gaining a few pounds of muscle. That will already have a dramatic impact on your physique, and then when you transition to bulking, you should be able to gain around a pound of muscle per week. If you started at 20% body fat, after 8 months (3 months cutting + 5 months bulking) you could expect to be at around 12% body fat with around 20 extra pounds of muscle on your frame.

Figuring out your body fat percentage is fairly simple, but staying lean while bulking requires a great system, as does cutting. If you want more guidance on how to do that properly, we can walk you through everything with The Bony to Beastly program.

17 Comments

  1. NickA on November 23, 2017 at 4:11 pm

    Great article guys. This is a solid guide for people to decide how far to take their bulking/cutting cycles. I’m in a bulk right now and feeling fat, so this makes me feel a tad better about my ever-growing gut. I thought I was somewhere around 17-19%BF but based on the article, maybe more like 15%. Let the permabulk continue!

    • Shane Duquette on November 23, 2017 at 5:46 pm

      Glad you dug it, NickA! Always good to hear from you, man 🙂

  2. CT on November 24, 2017 at 2:52 am

    Hey man,
    Firstly can I just say I love this site and it’s great to see some bodyfat percentage charts showing naturally skinny dudes. So much of this info is for bulkier guys with shorter limbs and it’s just way too hard to compare.
    I have a few questions about this though:
    1) are all these shots taken on an empty stomach? And what’s the relative level of hydration? I’ve been bulking properly for the first time in my life really for the last couple of months and I thought I was developing a gut, but when I took a few days off eating like a horse my gut dropped away. Out of curiosity I measured it after big meal at the end of the day vs first thing in the morning on an empty stomach and there was over 3″ difference. That was enough to drop my bf% from 17 to 12 according to an online calculator. Obviously that’s bs but how does bloat factor into a visual assessment?
    2) I am a soccer player and my legs are relatively bulky with good muscle definition while my torso and arms are much less muscley. I’m figuring that bf% is important hormonally because of the ratio of fat to muscle, so if my legs are comparatively bigger how does that affect my assessment of my % when all the photos (all over the web, not just here) only show from the waist up? A guy with the same torso fat to muscle ratio but skinnier legs would have to have a worse bf% surely because his total muscle mass would be much less but his fat would be about the same (seeing as fat isn’t carried evenly across the body but instead is concentrated around the lower torso in guys).
    3) is vascularity a useful indicator? I’ve seen it discussed a lot in the endomorph/mesomorph world of regular bodybuilding websites but I don’t see it here.

    I want to know where I’m at bf-wise so I know when to start cutting. I’m enjoying putting on weight and filling out shirts more but I don’t want to wake up one day and find out it was all fat!

    Thanks in advance for your help 🙂

    • Shane Duquette on November 24, 2017 at 11:04 am

      Hey CT, thanks for the kind words, man!

      And congratulations on your gains 🙂

      That’s a great question.

      1. As a general rule of thumb, we recommend weighing yourself, measuring yourself and taking progress photos first thing in the morning on an empty stomach. I’m guessing many of our members follow this advice… but I’m sure some don’t. I’m making my guesses based on the assumption that they’re measuring on a relatively empty stomach, though.

      2. As you mentioned, all of these male body fat comparison charts and photos focus on the stomach because that’s where men tend to store most of their fat. The whole reason why abs are so desirable on men is because when that area is lean, it indicates leanness elsewhere as well. So that’s the logic behind it, as you surmised.

      As for what to do when you have exceptionally muscular legs… I see the dilemma. A 150-pound guy with 15 pounds of fat has a body fat percentage of 10. If you were to gain 15 pounds of muscle in your legs without gaining any fat, you’d be a 165-pound guy with a body fat percentage of 9. So it will affect your overall body fat percentage, yes, and it won’t show up in your upper body.

      However, 15 extra pounds of muscle in your legs is a lot of muscle, and that’s just throwing off your body fat estimate by 1%. I wouldn’t even worry about it. If you do factor it in, you could instead bulk up until you appear to be around 16%.

      3. Vascularity is a useful indicator, sure, but it’s a lesser indicator compared to how much fat you have in your midsection. When you become vascular, that’s awesome, and it’s a great sign, but I would still guesstimate your body fat percentage primarily based on your stomach.

      I hope that helps!

  3. onesnowman on November 26, 2017 at 5:39 pm

    What body fat percentage do you think Cristiano Ronaldo is, Shane?

    • Shane Duquette on November 27, 2017 at 6:05 pm

      Hey Onesnowman, glad to hear from you here, man!

      I’ve seen Cristiano Ronaldo looking between 8–12% body fat, depending on the day. He’s quite lean and not overly muscular, giving him a body composition that most ectomorphs could very realistically achieve 🙂

  4. ajay on November 27, 2017 at 12:38 am

    first i am sorry for posting it here .couldn’t find the appropriate place .does anyone here have experience with squatting and deadlifting 3 times or more per week (not in a single workout) .and what was the effect on them ?of course assuming sleep and nutrition being good

    • Shane Duquette on November 27, 2017 at 6:14 pm

      Hey Ajay, no problem.

      Check out this article on leg training:
      http://bonytobeastly.com/how-big-should-you-build-your-legs/

      If you still have any questions, you can repost this question there (or write up a new one).

      (We might delete this question because it has nothing to do with body fat percentage.)

  5. Adil on December 3, 2017 at 2:54 am

    Nice article once again, Shane!
    You must be putting in a lot of effort researching and maybe even more typing it down in a fun to read comprehensive format.

    I had a question. You might have already looked into it…
    In which order does an ectomorph body eat up its calorie store types in starvation (given that he is not lifting any weights) ?
    For example, I have some belly fat, I decide to get rid of it. So i continue eating a little bit less- generally.
    Would my body, to make up for the caloric deficit, consume that fat in the belly first?
    Or will it be any leftover glycogen in my muscles or would it go straight to my precious muscles and cause their atrophy first?

    Regards
    Adil

    • Shane Duquette on December 3, 2017 at 1:58 pm

      Thanks, Adil!

      We’re lucky enough that there are a lot of great professional research analysts who publish research reviews, such as Alan Aragon’s Research Review, Stronger by Science’s M.A.S.S. and Strength & Conditioning Research. Dr. James Krieger used to have a great one as well. We read through all the research reviews each month, and that’s where we get a lot of this information. It’s also great that a lot of the most well-respected researchers write textbooks, such as Brad Schoenfeld’s Science and Development of Muscle Hypertrophy 🙂

      Sometimes, such as in our Ectomorph Aesthetics article, we’ll need to read through several dozen studies ourselves, but these guys are really making our job a lot easier 🙂

      Okay, on to your question. So if you were to really starve yourself over a long period of time, your body would break down everything. It would break down fat for energy and fatty acids, glycogen for energy as glucose, and muscle for energy and amino acids. You’d get smaller in every way. That’s one reason why starvation diets are so horrible for most people. But that’s an extreme case.

      If your calorie deficit is more modest, your body will have a certain amount of control over where it gets its energy from. If you’re sleeping well, you aren’t overly stressed, and you’re lifting weights, it will be more inclined to burn fat for energy. Your body considers the muscle necessary, since you require all of it for your consistent weightlifting routine, and since the situation is under control, it isn’t forced to break down any. Still, if you aren’t eating enough protein, it will need to break down muscle to get the amino acids it needs (for your hair, nails, etc).

      So if you’re sleeping well, not overly stressed, lifting weights and eating enough protein, that will cause your body to get the energy it needs exclusively from glycogen and fat, leaving your muscles entirely intact. This is what we call “cutting,” where we lose fat without losing muscle.

      Now let’s say that you aren’t doing those things. Then it will depend on your genetics and how lean you already are. An obese person will tend to lose mostly fat. A lean person will tend to lose mostly muscle. That’s why for the readers of this site, who don’t tend to have body fat percentages much over 20%, we never, ever recommend trying to lose weight unless they’re lifting weights and eating enough protein. Otherwise, they’ll lose mostly muscle.

      I hope that answers your question!

  6. Adil on December 3, 2017 at 3:51 pm

    Of course, by “research” I meant extensive browsing and studying the actual research.
    But the fact remains that as much as these researchers have made the job easier for you, you guys have made it even easier for us.
    And on top of all that you have made it commonly practically applicably doable.

    So to summarise, will the following be correct…?
    1- Prolonged Starvation:
    Fat = Glycogen = Muscle catabolism

    2- Moderate Starvation (whilst good sleep, mood and weightlifting)
    Fat = Glycogen > Muscle catabolism

    Optimal Diet (whilst good sleep, mood and weightlifting)
    Fat and Glycogen catabolism only (muscle protein is spared)

    Any more relevant scenarios?

    I wish I had you as a study partner at medical college and I wish they laid more emphasis on these details while teaching us Metabolism there.

    • Shane Duquette on December 4, 2017 at 11:47 am

      Yes, that’s the general idea. Genetics and circumstance will always play a role, but in general you’ve got it exactly right 🙂

      Regarding medical school, one problem with autodidacts, like myself, is that we often get our specialized knowledge without being forced to learn the foundational knowledge that underpins it all… which makes it hard to understand how everything fits together. (This is why we have Marco, who DOES have that extensive formal education in this field.) So while you may wish that your education covered more of this stuff, I wish my own education had more emphasis on the foundational knowledge—biology, organic chemistry, anatomy, metabolism, etc—in addition to this more specialized knowledge 😛

      • Adil on December 5, 2017 at 2:14 am

        Yup, life is too short to get everything in and even
        shorter to make all of it come together this way.

  7. Damien on December 4, 2017 at 10:27 am

    Thanks for the article Shane. Good day to you all guys.

    • Shane Duquette on December 4, 2017 at 11:40 am

      My pleasure, Damien. Glad you dug it 🙂

  8. Krsiak Daniel on December 7, 2017 at 3:16 am

    Great article Shane 🙂

    You have typo there, search for: “around around”

    • Shane Duquette on December 7, 2017 at 10:09 am

      Fixed! Thanks, DanielK 🙂

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