Bodybuilding Articles

Your Maximum Muscular Bodyweight and Measurements


Your Maximum Muscular Bodyweight and Measurements, by Casey Butt, Ph.D.

For a drug-free athlete trying to develop maximum muscle mass, the knowledge of how much muscle can be developed without the use of anabolic drugs would be a very valuable asset.

Unfortunately, because of the achievements of drug-using professional, amateur and recreational bodybuilders, many natural lifters either have no idea of their actual potential, they over-estimate what they can realistically achieve or they adopt a defeatist attitude and set their goals too low. Perspective is needed.

For a drug-free athlete trying to develop maximum muscle mass, the knowledge of how much muscle can be developed without the use of anabolic drugs would be a very valuable asset. Unfortunately, because of the achievements of drug-using professional, amateur and recreational bodybuilders, many natural lifters either have no idea of their actual potential, they over-estimate what they can realistically achieve or they adopt a defeatist attitude and set their goals too low.

Perspective is needed. The ability to set ambitious, yet realistic, goals is needed. And while there is no doubt that through natural bodybuilding a trainee can develop truly impressive, strong muscles, the chances of a drug-free bodybuilder attaining lean 22″ arms are about the same as him sprouting wings.

Maximum muscular bodyweight and size potential are positively correlated with a person’s height and bone-structure. Reflecting that, there are several formula in popular use that predict a person’s maximum muscular weight based on these variables (with bone-structure size typically estimated by measuring the circumference of the wrist).

Bodybuilding legend Steve Reeves presented simple formulas for calculating what he considered to be ideal muscular weight. He suggested starting with a base of 160 pounds and adding 5 pounds for every inch of height above 5’5″. For people above 6’0″, he suggested starting with 200 pounds and adding 10 pounds per inch. Using these formula, a person 5’9″ would have an ideal muscular weight of 180 pounds. A person 6’1″ would weigh 210 pounds. The problem with these predictions is that they do not consider bone structure size.

In his book, Beyond Brawn, Stuart McRobert also proposed a method of estimating maximum muscular bodyweight. The suggestion is to start with 5’0″ as a base height and 100 pounds as a base weight. Then add 10 pounds for every inch of height above 5’0″ for a medium bone structure, 8 pounds for a small structure, and 12 pounds for a large structure. Above 5’9″ add only half those amounts. A person of 5’9″ with a medium structure would weigh 190 pounds. A person of 6’1″ with a large structure would weigh 232 pounds. This is a worthwhile refinement of the simple linear approach, but becomes inaccurate when dealing with very large and/or very small structured people.

In the scientific community, Dr. E. M. Kouri, et. al. presented a comparison between the lean body masses of drug-free vs. drug-using lifters based upon their fat-free mass indexes (FFMI) [1]. This formula can be solved for maximum lean body mass at a given height if a maximum FFMI is assumed for drug-free lifters. The problem with doing this, however, is that, again, bone structure is not considered.

What’s needed is an accurate and precise formula, based on personal bone structure and height, that gives the maximum lean body mass a trainee can achieve without the use of anabolic drugs.

Predicting Maximum Muscular Bodyweight

The average male serum testosterone level is between 2.7 and 10.7 ng/ml. This imposes a limit on the amount of lean body mass that can be developed and maintained without the use of exogenous anabolic drugs (women’s testosterone levels are 20 to 30 times less than this, resulting in less muscle mass potential). Muscular potential is also influenced by muscle belly length, fast-twitch to slow-twitch fiber ratio, etc. So there will be variations in potential between people even of identical bone structures. Consequently, no equation predicting maximum muscular bodyweight will be 100% accurate for everybody.

What such an equation can do, however, is establish an upper limit of potential based on the achievements of drug-free bodybuilding champions. These men possess naturally high testosterone levels, full muscle bellies, and the host of structural characteristics that permit the development of world-class physiques – they reflect the upper limit of male drug-free muscular potential. Therefore, a muscular bodyweight prediction equation based on such a group of men provides an estimate as to the maximum muscular size a person of a given structure is likely to achieve without the use of anabolic drugs and while maintaining a “balanced” physique.

If you have long muscle bellies, good health and hormone levels, a growth supporting diet and lifestyle, and train according to your needs then you should, in time, be able to reach such a predicted muscular weight. If one of these factors doesn’t apply to you then your potential will be less. It has been my experience, though, based on over 5 years of data collection and analysis, that most healthy people can come quite close to what such a formula can predict – if they train correctly for long enough.

One must also consider the case where a person’s bone structure tapers at the extremities. For instance, the wrist and ankle circumferences could be “small” but the upper legs and torso structures not correspondingly “small”. This trait is somewhat common amongst people of African descent. Some people with strong endomorphic tendencies also have this type of structure. The opposite end of the spectrum is a very slightly built person who has large wrists and ankles. This type of structure also exists. In these cases, it is more difficult to accurately predict muscular potential. I have chosen to present a simplified lean body mass prediction equation, but with the caveat that an adjustment be made for very thinly and thickly built men.

Finally, potential lean body mass increases with body fat percentage. Research has found that very heavy Sumo wrestlers actually carry more lean body mass than bodybuilders of the same height [2]. I performed a statistical analysis of off-season vs. contest-condition bodybuilders to account for this in the lean body mass prediction equation.

Predicting Maximum Muscular Bodyweight: The Equation

The equation below predicts the maximum lean body mass someone of a given height and bone-structure can achieve without the use of anabolic drugs (there is a link at the end of this article to an online calculator based on all of the formula presented here).

Maximum lean body mass = (3.285H + 9.437A + 5.840W – 186.449) x (%bf / 227.27 + 1)



      H = Height in inches


      A = Ankle circumference at the smallest point


      W = Wrist circumference measured on the elbow side of the styloid process.


      (The styloid process is the bony lump on the outside of your wrist.)


    %bf = The body fat percentage at which you want to predict your maximum lean body mass

Very thin ectomorphic men can expect to attain about 95% of the lean body mass that the equation predicts. Likewise, very endo-mesomorphic people, who have disproportionately wide hips and thick torsos, and people whose joints are uncharacteristically small, may be able to exceed the prediction by up to 5%.

So, using this equation, for a 5’9″ (69 inches) tall bodybuilder at 10% body fat with 7.0″ wrists and 8.7″ ankles the equation would yield:

Maximum lean body mass = (3.285 x 69.0 + 9.437 x 8.7 + 5.840 x 7.0 – 186.449) x (10 / 227.27 + 1) = 170.4 pounds.

To convert maximum lean body mass to maximum bodyweight at any given body fat, use this equation:

Body weight = (Lean body mass / (100 – %body fat) ) x 100

Using our example bodybuilder, at a lean and healthy 10% body fat his total bodyweight would be:

Body weight = (170.4 / (100 – 10) ) x 100 = 189.3 pounds

The formula was developed as an amalgamation of data from past and present drug-free bodybuilding champions and anthropometrics data from the U.S. Army, Navy, and several anthropometrics studies done by various organizations throughout the world (for ergonomic designs, etc.). In addition, a comparison was made with the fat-free mass indexes of champion bodybuilders, as presented in the work of Dr. E. M. Kouri, et. al. A mathematical regression was done to obtain fits based on the heights, wrist sizes and ankle sizes of elite-level drug-free bodybuilding competitors. As the final fit was sufficiently linear in nature, the equation was then linearized to make it more “user-friendly”, without sacrificing accuracy.

Table 1 presents a list of drug-free bodybuilding champions both past and present with their actual weights and the weights predicted by the formula. The current champions are unnamed because of the “sensitive” nature of body weights and measurements to actively competing bodybuilders.

Table 1: Bodybuilder Actual Weight Predicted Weight
Clarence Ross 198 198.1
John Farbotnik 195 196.2
George Eiferman 195 195.5
Reg Park 214 214.5
John Grimek 203 203.1
Jack Delinger 195 193.3
Steve Reeves 213 214.1
Current World Champ. “A” 180 180.7
Current World Champ. “B” 175 174.6
Current National 3rd Place 174 174.0
Current National 4th Place 184 185.5

The greatest error in the above predictions is 0.87%. So, as you can see, the equation is quite accurate for this group of bodybuilders. In addition, these lifters are of varying heights and bone structures to further illustrate the validity of the predictions.

If you are lifetime drug-free, use this formula to set a realistic and accurate bodyweight goal for yourself. If you’re like our example bodybuilder of 5’9″ tall, with 7″ wrists and 8.7″ ankles, then forget about weighing a lean 230 pounds. If you get to a lean 190 pounds you’ll be carrying as much muscle, with respect to your frame, as an elite-level natural bodybuilder.

Predicting Maximum Muscular Measurements

There have been several sets of equations presented over the years that attempt to predict maximum muscular measurements based on height or wrist size. The problem is they typically don’t consider both, and very few of them consider lower body structure size. A popular set of formula was presented by bodybuilding author John McCallum in the mid-1960s. All predictions were based on wrist size, without the lifter’s height taken into consideration. Such an approach can be sufficiently accurate for a lifter of average stature but muscular potential is, to a degree, influenced by height. For instance, a 6’1″ tall trainee with an 8″ wrist will, generally, have the potential to develop larger muscular measurements than a 5’8″ trainee with an 8″ wrist. Height must be included in such predictions.

Using a similar procedure as I did in deriving the bodyweight formula, I derived a set of equations that predict muscular measurements in lean condition. Again, height, ankle circumference and wrist circumference are the determining factors. One caveat is in order: People with uncharacteristically small joints for their frames (notably some people of African descent) may be able to exceed these predictions by 5-7%.

      chest = 2.222W + 1.796A + 0.347H – 9.514


      biceps = 1.609W + 0.126H – 3.444


      forearms = 1.280W + 0.100H – 2.740


      neck = 1.561W + 0.122H – 3.342


      thighs = 1.872A + 0.181H – 4.957


    calves = 1.257A + 0.122H – 3.330
      Measurement Procedure:


      chest – measured relaxed (not expanded), arms at sides, tape under armpits


      biceps – flexed, at largest point


      forearms – fist clenched, hand out straight, measured at largest point


      neck – below Adam’s apple at smallest point


      thighs – standing relaxed, midway between hip and knee


      calves – standing relaxed, at largest point


    * For all measurements tape should be snug but not tight.

For our 5’9″ trainee with 7.0″ wrists and 8.7″ ankles we have:

      chest = 2.222 x 7.0 + 1.796 x 8.7 + 0.347 x 69 – 9.514 = 45.6″


      biceps = 1.609 x 7.0 + 0.126 x 69 – 3.444 = 16.5″


      forearms = 1.280 x 7.0 + 0.100 x 69 – 2.740 = 13.1″


      neck = 1.561 x 7.0 + 0.122 x 69 – 3.342 = 16.0″


      thighs = 1.872 x 8.7 + 0.181 x 69 – 4.957 = 23.8″


    calves = 1.257 x 8.7 + 0.122 x 69 – 3.330 = 16.0″

Yes, that’s a far cry from what some drug-using bodybuilders are achieving. But, like it or not, those numbers represent the maximum measurements that a natural trainee is likely to achieve without drugs, while still maintaining balanced measurements throughout the body. In reality, any trainee who reaches the measurements predicted by these equations will be an impressive physical specimen …he would have the size and proportions of the bodybuilding legends listed above and of the current drug-free bodybuilding champions.

As an illustration, Table 2 shows how the old-timers and drug-free elite competitors from 2006 “measured up”, along with the predictions of the equations. The actual measurements were taken from a variety of sources that I deem credible, and were taken at body fat levels of approximately 8-10%.

Table 2: Measurements of Drug-free Bodybuilders
Chest Biceps Forearms Neck Quads Calves
Bodybuilder actual/pred actual/pred actual/pred actual/pred actual/pred actual/pred
John Farbotnik 47.5 / 47.8 17.0 / 17.3 13.5 / 13.8 16.8 / 16.8 24.5 / 24.9 15.7 / 16.8
George Eiferman 47.5 / 47.4 16.7 / 16.8 13.4 / 13.4 16.5 / 16.3 25.0 / 25.2 16.0 / 17.0
Reg Park NA / 50.8 18.5 / 18.6 NA / 14.8 18.0 / 18.1 26.5 / 26.2 17.5 / 17.6
John Grimek 49.9 / 49.7 18.3 / 18.1 14.5 / 14.4 17.7 / 17.5 25.7 / 25.9 17.3 / 17.4
Jack Delinger 47.5 / 47.7 17.2 / 17.3 13.8 / 13.8 16.8 / 16.8 25.0 / 24.9 16.6 / 16.7
Steve Reeves 49.5 / 49.8 18.0 / 18.0 14.5 / 14.3 17.5 / 17.4 26.0 / 26.0 17.9 / 17.5
Current World Champ. “B” NA / 44.4 16.7 / 16.2 NA / 12.9 15.5 / 15.7 23.0 / 23.1 16.0 / 15.5
Current National 4th Place NA / 47.1 17.2 / 17.2 NA / 13.7 17.0 / 16.7 24.5 / 24.4 15.5 / 16.4

Again, the predictions are quite accurate, but they also help illustrate certain points. For instance, you’ll notice that many of these bodybuilders have calves smaller than the predicted values, whereas Steve Reeves and World Champion “B” exceeded the predicted values. What you are seeing there is the fact that the calves are a notoriously difficult body part to develop, whereas these competitors were genetically blessed with great calves that responded well to training. Also, World Champion “B”‘s arms exceed the prediction by 1/2” in the off-season – he is known for his outstanding arms. It is interesting to note, though, that in contest shape his arms “only” measure 16.0″.


What these equations give you is the heaviest lean body mass and largest lean measurements that a natural bodybuilder of the given structure is likely to achieve while maintaining balance throughout the muscle groups of the body. That isn’t to say that a bodybuilder won’t have a genetically gifted body part(s) that exceeds these predictions, or that he can’t surpass these predictions by specializing, perhaps inappropriately, on certain muscle groups. However, it is very unlikely that the rest of the physique, as a whole, would reach that standard. If you have body parts that can exceed the predictions then you’ll probably always have to “take it easy” on those muscles or they’ll grow out of balance with the rest of your physique. (And if your outstanding body part is a large muscle group like legs or back this can cause your bodyweight to exceed the prediction given by the bodyweight equation.) In this regard, these equations should be viewed more as maximum guidelines than as limitations. On the other hand, perhaps you would like your biceps a little oversized with respect to the rest of your physique.

Also, keep in mind that achieving these measurements doesn’t necessarily mean that your body will be “perfect”. Measurements don’t tell the full story – things such as muscle shape, symmetry, separation and definition can make all the difference. You may find yourself achieving these measurements yet your physique still lacking in certain aspects. Most commonly, if a person reaches these predictions, yet still doesn’t appear muscularly impressive, then he’s simply too fat – keep in mind that these equations describe a lean condition. On the other hand, if your measurements are significantly under what the equations predict, it probably means you’ve got some growing left in you yet.
Reg Park In reality, it will take years of dedicated, productive training for most genetically typical trainees to even approach these predictions. Most people will never achieve this level of development …and measurements taken at higher body fat levels do not reflect true muscular development.

In closing, I want to stress that although these formulas present lofty, but realistic goals for most drug-free trainees, they are not meant to represent “limitations”. But you also must realize that in the process of surpassing these predictions you are also surpassing the development of drug-free world champions. Very few people will have the genetic gifts to accomplish that. What the formulas give you is the lean body mass and full-body measurements that you’d need to achieve to be on an equal footing, size-wise, with current drug-free champions and the greats of the drug-free era. I’m not saying that no one can surpass that, but to put it in perspective, you’d need to be carrying more muscle (with respect to your skeletal frame size) than a prime Reg Park in order to do it.

Online calculator based on the formulas presented above: Your Maximum Muscular Bodyweight and Measurements Calculator

Kouri E.M., Pope H.G. Jr., Katz D.L., Oliva P., “Fat-free mass index in users and nonusers of anabolic-androgenic steroids”, Clinical Journal of Sport Medicine, vol. 5, no. 4, pp. 223-8, 1995.
Kondo M., Abe T., Ikegawa S., Kawakami Y., Fukunaga T., “Upper limit of fat-free mass in humans: A study on Japanese Sumo wrestlers”, American Journal of Human Biology, vol. 6, no. 5, pp. 613-18, 1994.

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Casey Butt
Casey Butt runs He is a PhD, and has authored articles for Milo and Hardgainer.
  • Anon Jan 11,2014 at 3:37 am

    Pure research.

  • Chris Jan 10,2012 at 2:57 pm

    Good articles. I appreciate the research that you are doing, and you have a good muscular development too. But, you keep assuming that John Grimek and Steve Reeves were natural bodybuilders. John Grimek was on testosterone (look it up on Wikipedia), and Steve Reeves is reputed to have used dianabol. Sergio Oliva said that Steve Reeves introduced him to dianabol. T has been around since the Nazis.

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