Here’s How Much Muscle You Can Gain Naturally, Including A Free ‘Genetic Potential’ Calculator 

“How much muscle can I gain naturally?” A question that every person with even a passing interest in fitness has asked. But what’s the answer?

Most will say it’s impossible to say. There are too many variables. And, of course, “…it depends.”

And while it’s not an exact science, there is a way of assessing your genetic potential and how much muscle you can build.

In this article, you’ll discover what defines your genetic potential, how to calculate how much muscle you can gain, and how to fulfil that potential. With that said, here’s what the article covers:

• The factors that define your genetic potential.
• 2 online calculators to help you easily work out how much muscle you can potentially build naturally.
• A method for assessing if your goals are achievable without drug enhancement.
• A guide on how to determine if your favourite social media personality is as drug-free as they claim.
• Another online calculator to help you determine how much muscle you can build in a year.

So, if you want to find out more, read on.

What Factors Define How Much Muscle You Can Gain?

Before we launch into calculating how much muscle you can build, let’s look at the factors influencing what’s possible.

Genetics play a huge role in defining your potential. After that, the quality of your training and nutrition determines how much of that potential you fulfil. In my experience, most people who blame genetics or claim to have hit their genetic ceiling are not even close.

In reality, building muscle is hard. It takes consistent effort over a long period of time. And most people aren’t prepared to put in that work. So they resort to, “…it’s my genetics” as the default excuse.

That said, there is an obvious genetic component to the discussion. So here’s what the research tells us about what’s involved in determining how much muscle you can build.

Birth Weight:

According to a 2007 study, higher birth weight is positively associated with greater long-term potential for muscle gain. In fact, for every 1kg difference in birth weight, you can expect c. 4.1 kg of muscle gain over a lifetime.

Initial Lean Mass:

A study in 1994 looked at potential muscle gain over a 12 week period, based on subjects’ starting levels of lean mass. The conclusion of the study indicated that the more muscle you have to begin with, the more you’ll gain over time.

Joint Size:

An analysis of 501 participants looked at the association between ankle and wrist size, and free fat mass (FFM, i.e. muscle). It highlighted a positive correlation between greater joint size and increased FFM.

Wider Frame:

A 2007 study looked at the levels of FFM mass in powerlifters. The research showed a positive association between greater FFM and those athletes with wider frames.

So what conclusions can we draw from this?

In a nutshell, your parents have a lot to answer for. Ultimately, how much muscle you can potentially gain over your lifetime is out of your hands. Although it’s worth bearing in mind, these studies are looking at associations. Consequently, they’re not designed to provide strict limitations. After all, you may be an outlier who defies the trend.

How To Calculate How Much Muscle You Can Build?

Based on the available data, many formulas have been developed to help calculate your genetic potential. The simplest of which is based on height. But these don’t cater for variances in physiques. For example, according to these calculations, a taller person will have the potential to build more muscle than a shorter person. However, we’ve all seen that short, heavy-set dude badass in the gym.

Casey Butt developed a formula to account for this. It’s more complicated, which is why I’ve simplified it for you in this handy calculator. Sadly, his research only involved men, so it’s probably not accurate for women.

For this calculation, you’ll need to know your:

• Height (cm)
• Ankle Circumference (cm). Measure at the smallest point.
• Wrist Circumference (cm). Measured at the Styloid Process (the boney lump).
• The body fat % at which you want to predict your maximum lean body mass. It’s recommended you pick 8-10% here. Any lower probably isn’t sustainable for very long.

Other Evidence-Based Methods For Calculating How Much Muscle You Can Build

Casey Butt’s formula isn’t the only method for calculating how much muscle you can build. Martin Berkhan has developed an incredibly simple calculation based on his experience in coaching thousands of people to get very lean.

His calculation is based on your weight at competition levels of body fat (5-6%). So “lean AF” to give you the technical definition:

The calculation: Stage Lean Weight = Height (cm) – 100 (instead of subtracting 100, you can use 98 & 102 to provide a range).

Calculating Your Competition Weight Potential:

If you’re interested in using Martin’s formula, use the calculator below to understand your maximum body weight at 5-6% body fat.

A word of caution! As this calculation is purely based on height, there’s minimal consideration for genetic differences. Again, treat it as a guide, not an absolute.

Also, it’s sadly only for dudes (sorry ladies, I didn’t make the formula).

Is That Dude Natural? A Calculator To Help You Find Out…

You might surf through social media and wonder if the physiques you see daily are achievable without a trip to your local ‘underground pharmacy’.

Often, comparing yourself to others leaves you disheartened and deflated about your own progress. And, in many cases, these models and athletes claim to the bitter-end they achieved everything naturally. But did they really? In many cases, you can rely on what they say about as much as the bullshit supplements they’re trying to sell.

But it’s easy to dismiss any well-sculpted physique as the product of steroids.

So how do you know who’s telling the truth and who isn’t? The answer is, unless the dude (or dudette) is freakishly big, you DON’T!

And, unless said person is trying to pull the wool over your eyes for their own personal and financial gain, does it even matter?

Understanding Your Genetic Potential

Being accused of steroid use is something I’ve dealt with in the past. As a natural bodybuilder, the social media trolls flick between the extremes of “Do you even lift?…” and “Must be on the juice!” with a baffling degree of idiocy.

For example, take a look at these pictures.

After posting this picture online, I received multiple comments that my transformation was only achieved through steroid use (which it definitely wasn’t).

Weirdly, this picture (taken over a year later) had the same keyboard warriors wondering if I even lift. P.S. I actually have MORE muscle in this pic!

So, the lesson here is that body fat, lighting, angles, and high-quality photography can enhance the look of any physique.

That aside, there IS a way for you to assess if someone is or isn’t bending the genetic rules.

Eric Helms developed a calculation based on the Free Fat Mass Index (FFMI). Using data from a study of 83 steroid users and 74 non-steroid users, Helms’ calculation estimates how much muscle can be built naturally.

The calculation: FFMI = fat-free mass in kilograms/(height in meters)²

Calculating Your (Or Someone Else’s) Genetic Potential:

You can use the calculator below to assess your own FFMI and genetic potential. Enter your height, desired body weight, and target body fat percentage. Then the calculator will give you an FFMI score, which you can use to determine if your goals are achievable naturally. And if you know the vital statistics of your favourite Insta model, you can use the calculator to assess their physique as well.

Interpreting your FFMI:

• 16 – 17: below average
• 18 – 19: average
• 20 – 21: above average
• 22: excellent
• 23 – 25: superior
• 26 – 27: scores considered suspicious but still attainable naturally
• 28 – 30: highly unlikely scores to be obtained naturally without steroid usage

As a guide, an FFMI score of 25 is the ceiling for most natural bodybuilders.

Word of caution! Measuring your body fat is highly inaccurate unless you have access to a DEXA scan. So bear this in mind when you are assessing how much muscle you’re able to build.

Sadly, the study used to develop these calculations used exclusively male athletes. Again, this means there may be a degree of inaccuracy for females (sorry ladies!).

How Much Muscle You Gain Comes Down To Training And Nutrition

Genetics aside, your ability to build muscle is driven by what you do in and out of the gym.

You can have the best genetics in the world, but if you train poorly and half-ass your nutrition, you’ll fall short of your potential. So it’s important to focus on putting the basics in place as soon as possible. Then, with consistent execution, you’ll begin to build muscle to the extent your genetic potential allows.

And if you’re unsure where to start, use these “Fuck-Ton Of Muscle Starter Kit” infographics to help.

In summary, your priority number one is training. Basically, without the appropriate stimulus, your muscles won’t adapt and grow.

The Bottom Line On How Much Muscle You Can Gain Naturally

How much muscle you can gain naturally is largely driven by your genetics. Picking good parents is likely to be the biggest determining factor in the amount of muscle you build. But you still need to do everything right to get anywhere near your genetic potential.

Factors outside of your control may dictate the ceiling for how much muscle you can build, but this shouldn’t deter you from giving your all to training.

Research indicates your genetic potential. However, this isn’t a fixed limit. And there will always be exceptions and variations to the rule.

Also, there’s the small matter of needing to everything right along the way.

In truth, most people never come close to their genetic potential. Ineffective training and sub-par nutrition results in years of mediocre gains. So unless you’ve genuinely maxed out on how much muscle you can build, continue to focus on the basics of training and nutrition. Develop consistency, enjoy the process, and let time take its course.

“But Simon. How much muscle can I build in a year? How do I know if I’m progressing at the right speed?”

Good question. And the next logical progression after assessing how much muscle you can build over the long term.

Thankfully, there’s an evidence-based way to set your expectations.

How Much Muscle Can You Gain In A Year?

Lyle McDonald has developed guidelines for determining your rate of muscle growth, based on the years of training under your belt.

• 1 Year Of Proper Training = 20-25 lbs of lean muscle per year
• 2 Years Of Proper Training = 10-12 lbs of lean muscle per year
• 3 Years Of Proper Training = 5-6 lbs of lean muscle per year
• 4+ Years Of Proper Training = 2-3 lbs of lean muscle per year (not worth calculating)

The important thing to note here is that the estimations are based on the number of years of proper training AND nutrition. So, throwing a few weights around, attending a few body pump classes, and being lax with your nutrition, doesn’t count.

In fact, if this is you, class yourself as a newbie when using the calculator.

The “How Much Muscle Can I Gain In A Year?” Calculator:

Using Lyle’s guidelines, here’s a simple calculator you can use to set your expectations for the next 12 months. And if you HAVE been managing your training and nutrition properly for several years, the news is bleak. In fact, I’ve not even included you in the calculations, because your rate of muscle gain is almost immeasurable.

Want To Kickstart Your Nutrition To Help Build The Most Muscle Possible Over The Next 12 Months?

After reading this article, you might be excited at the prospect of transforming your physique and fulfilling your genetic potential. And to do that, you need training, nutrition, and mindset to be aligned. One thing that’s important to get right is your calorie intake. If you’re fuelling your body and training sufficiently, you’ll build more muscle. And if you eat the right amount of protein, you’ll turn your efforts in the gym into muscle and visible change to your physique.

Click this link to get free access to my online calorie and macro calculator. You can calculate the right calorie target and start making progress, today. And as an added bonus, I’ll send you the Lean Life Kickstarter pack.  You’ll get a free 4-week training programme to help kickstart your training, as well as recipe packs, and a complete guide to calories and macros.

To kickstart your journey to a leaner, healthier life, click here.