I got Arnold’s Encyclopedia of Bodybuilding when I was 13 years old.

I followed his training plans to the letter.

I ate the exact foods he recommended in the exact amounts he recommended. I was a zealot.

Because I honestly believed if I worked hard enough, I could one day be as big as Arnold.

These days I know better. No matter how hard I train, no matter how perfect my diet… I’ll never be as big as Arnold at his peak.

 

While that might sound disappointing, it’s not. Because knowing the truth about what you can expect from your workout plan is far more valuable than falling short of an unrealistic expectation.  So in this article, I’ll share a simple formula you can use to accurately predict your maximum muscular size and body weight.

It’s All In The Wrist

 

A simple way to determine your maximum muscular arm size starts with measuring your wrist.

Because it’s the size of your skeleton or your “frame” that determines the upper limit of how much muscle you can hope to carry. A guy with a thick frame, big bones and large joints will be able to carry more muscle mass than a person with narrow shoulders and thinner bones.

The wrist measurement gives you an accurate read on the size of your frame. This is because the wrist joint is mainly skin and bones without much muscle or fat to get in the way.  Here’s my own personal formula (created by studying the measurements from drug-free bodybuilders over the years) for calculating how big your arms can get while staying lean.

Loop a tape measure around your wrist to get your wrist measurement. A 6 inch wrist is considered small. A 7 inch wrist is average and an 8 inch wrist or bigger is considered large. Now take your wrist measurement and add 10 inches. This gives you a pretty good idea of how big your arm/bicep size can one day be (flexed) ASSUMING a lean physique.

Anyone can get an 18-inch arm by packing on fat. But a true 18-inch arm on lean person is extremely rare.

Now take your maximum arm size, double it and subtract 2 inches: This gives you the maximum waist size you need to stay under to achieve the desired degree of “leanness.”  Here’s a good example of a muscular, lean physique created without steroids.

 

This is a picture of Eugene Sandow, who died in 1925 – so we know he didn’t use steroids. (They weren’t invented until the late 1940’s.)

Like most bodybuilders, his measurements were embellished and exaggerated over the years. It’s not unusual to see his waist size listed at 28 inches or his arms stretching the tape at 18 inches.  But in 1893 his measurements were taken by Dr. Dudley Sargent in New York. Here are Sandow’s correct measurements as recorded by Dr. Sargent:

Wrist: 7.2 inches

Upper arms: 16.5 inches.

Waist: 32.7 inches.

As you can see, Sandow’s measurements are almost exactly in line with the formula above for maximum size in a drug-free athlete.

“I’ll be happy when I’m 225 pounds and ripped” – said every guy ever.

I hear the above sentiment almost daily. And on the surface, it seems doable. After all, if Joe Pro Bodybuilder is 300 pounds and ripped, shouldn’t the average guy be able to obtain 225 and ripped?

Probably not.

Here’s a simple formula that predicts your maximum body weight while ripped. (“Ripped” in this case means 6% body fat or less.) This formula was developed by Martin Berkham and in my experience, it’s frighteningly accurate.

 

(Height in centimeters – 100) = Body weight in kilo (“shredded”, i.e.5-6% body fat).

So if you’re 6 feet tall, that’s 182 centimeters. Minus 100 leaves you with 82KG. Multiply 82KG x 2.2 to convert to pounds and you’re left with 180lbs. That’s your maximum body weight assuming crazy lean conditions – (ie: 6% body fat).

Obviously, most guys will never get that lean. But you can alter the formula a bit by bumping it up. Adding 10 pounds will bump up the body fat percentage by approximately 2%.

So if you’ve got a 7 inch wrist, your maximum arm size while staying lean will be 17 inches and to achieve the lean look your maximum waist size will be 32 inches. (17 x 2 = 34 -2 = 32 inches.)

For a man who’s 6’0 feet tall…

Maximum Body weight @ 6% body fat = 180lbs. (Estimated waist size 30 inches)

Maximum Body weight @ 8% body fat = 190lbs. (Estimated waist size 31 inches)

Maximum Body weight @ 10% body fat = 200lbs. (Estimated waist size 32 inches)

As you can see, it’s highly unlikely that an average guy will ever be 225 pounds and ripped unless he’s A) extremely tall, B) taking steroids or C) simply a genetic outlier (which does happen.)

This is the rule (not the exception)

For some reason, whenever I share these formulas with people… they get angry.  They always want to talk about the exception to the rule, not the rule itself.

I feel these formulas hold up pretty well for 80% of the population.  There are probably some guys who will NEVER make it even close to these benchmarks, no matter how hard they train.  And on the other end of the spectrum, there are probably a tiny handful of genetically gifted athletes who will easily surpass the upper limits of these formulas.  But for most guys, these formulas will hold true.  Think of it this way:  Most men are between 5’10 and 6’2 in height.  This doesn’t mean you’ll never see a man who’s only 5’4 or another guy who’s 6’8.

But the existence of the tall man or the short guy does not change that fact that most men are between 5’10 and 6’2.  The exceptions do not disprove the rule.

If you feel you can do better than these formulas indicate… I hope you prove me wrong.   I hope you overachieve and surpass the limits of these formulas.

Train hard. Eat right. You might never be 225 and ripped, but you can still be a bigger, stronger, leaner version of YOU.

First time here?  Grab this free report now. 

References:

Martin Berkhan, “Maximum Muscular Potential of Drug-Free Athletes”, Lean Gains, http://www.leangains.com/2010/12/maximum-muscular-potential.html
George Russel Weaver, “What Is A Physique Like Sandow’s?” Superman Magazine, September 1938
Alan Calvert, The Truth About Weightlifting, published 1911, pages 97-108