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Anyone make a size breakdown bell curve? I mean...


Anyone make a size breakdown bell curve? I mean...

Now that I confused you, let me explain what I mean. Using math like standard deviations, etc. has anyone made a size breakdown bell curve? What I mean is that if you take the average, say 6” (or whatever) make a bell curve that with accuracy shows how many fewer people have 5” and 7”, 4” and 8”, etc. Based on standard deviation from an average point (say 6”) roughly the same number of people should have a measurement any given amount over that as number of people that same given amount under it. I guess that can’t be 100% true, because that would mean for every guy with a 12” there is a guy with 0” — well maybe that is true, who knows! I read in a post somewhere on this board that about 1 in 50 guys has 8” BPEL which, if accurate would mean that about 1 in 50 guys has a 4” BPEL. Again that’s assuming a 6” average, which I’m not sure is accurate I’m just using nice round numbers. Of course ALL the measurements we are speaking about are pre-PE. What do you guys think? Could such a bell curve be constructed? I assume it already has in one form or another but I have yet to see it. Oh and of course the same exact bell curve could be made using girth instead of length.

Visit for a table of sizes distributed like a bell curve.

EDIT: Had to remove the direct link, has a porn connection which isn’t allowed here.

"Fascism should more properly be called corporatism

because it is the merger of state and corporate power."

-Benito Mussolini

Last edited by westla90069 : 11-04-2003 at .

Hey, here’s my first post ever! I don’t know so much about the mechanics of enlargement, but I do know about math.

Seems the two most oft-quoted studies on this forum are the Kinsey and Lifestyles Condoms studies which give average lengths of 6.2 and 5.87 inches respectively. The Lifestyles study also gives an average girth of 4.97 inches. Seems like I remember seeing a standard deviation of length for the Lifestyles study too. It was something like 0.8 inches or something.

Couple of quick notes, though. First is to realize that a gaussian distribution only _approaches_ zero. This may seem counterintuitive since the right side appears to trail off into infinity while the left side stops abruptly at zero. It is a fact nonetheless. If you’re interested in a discussion of why, just ask sometime and I’ll be happy to bore you to tears.

The second thing is to realize that biological measurements are almost never reliable past the third standard deviation. Things which seem unnaturally rare in the biological world are exactly that. Unnatural. The normal span of variance that we expect to see has been screwed up somehow. Genetic mutation, extra genes (XYY syndrome), missing genes, effects of disease etc. When something seems really out of place, it’s usually a sign that something went wrong (but that doesn’t mean bad!).

A good examples of this is height. Average male height in America is about 70” with a standard deviation of 2.7”. Anyone over 7’6” is therefore “impossibly” rare (something like 1 in a 10 billion), yet we know that plenty of such people exist (“plenty” meaning perhaps 50, but that’s still about 100 times more than we would expect).

As a side note, if the average is 5.9 - 6.2 and the SD is around 0.8, then 8” would be just about 1 in 50 as you heard. But anything past 8.5” becomes an anomaly.

busted bus

Hi bustedbus. Nice first post. :)

The Definitive Penis Size Survey ranks sizes by percentile and also shows a bell-shaped distribution graph. EL is bone pressed.

In most of the studies I’ve seen girth is measured wherever it is the thickest. Girth numbers given here at Thunder’s are almost always midshaft, which for many guys isn’t the thickest part. Not a big deal, just something to keep in mind as you peruse various studies.

Hey bustedbus! Welcome aboard!

Mind telling us your personal breakdown of just what ranges are “anomalous” and freakishly rare etc? just out of your personal opinion, your own view of the breakdown of the bell curve… thanks!

Hey all, thanks for the welcome.

My own bell curve? I’d need to have a whole lotta measurements and then put them into some software. But the link that hobby shows above gives size distributions as a curve and by percentile. I don’t trust that particular survey because it relies on self-reporting. I assume that all the math is correct, just performed on “fibbed” numbers.

In case you’re wondering, +3 standard deviations is about the 99.87% range. If you believe that 6” is average and that 1 S.D. is 0.8”, then you would expect about 1 person in 750 to measure 8.4”.

Luckily we have PE to elevate us to unnatural and Freakish percentiles!!

Busted Bus

Bustedbus - would 7.6” be the 98th percentile, if 0.8” is the SD and 6” the average? (don’t remember stats too well)

Please :donatecar to Thunder's Place to keep it running.

Hey Stud,

Using 6” and 0.8” as our assumptions, figure it this way:

7.6” - 6” = 1.6”

1.6” / 0.8” = 2.0

So 7.6” would be 2 S.D. exactly. Then, if you’re lazy like me, you don’t even try to remember the formula. Instead you go here and look it up in the table.…ormalTable.html

Says +2 S.D. = 97.72%

On a different note, I checked out the Kinsey study again on another website. If we use their numbers (which I don’t like because of the poor protocol, but then they’re the only ones I could find who had figured a S.D.) then average would be 6.21” and S.D. is 0.77”. So we construct the small table below:

6.21” —-> +0.0 SD —-> 50% —-> 1 in 2
6.60” —-> +0.5 SD —-> 69% —-> 1 in 3
6.98” —-> +1.0 SD —-> 84% —-> 1 in 6
7.37” —-> +1.5 SD —-> 93% —-> 1 in 14
7.75” —-> +2.0 SD —-> 98% —-> 1 in 50
8.13” —-> +2.5 SD —-> 99.4% —-> 1 in 165
8.52” —-> +3.0 SD —-> 99.87% —-> 1 in 750

Anyone know how to get the raw data from some of the other studies?

Busted Bus

Not to be repetitive, but I was able to find info on the Lifestyles study here:

The average was smaller, but the SD was larger. 5.877” and 0.825”.

I’ll make another table anyway, then people can choose the table they trust more.

5.88” —-> +0.0 SD —-> 50% —-> 1 in 2
6.29” —-> +0.5 SD —-> 69% —-> 1 in 3
6.70” —-> +1.0 SD —-> 84% —-> 1 in 6
7.11” —-> +1.5 SD —-> 93% —-> 1 in 14
7.53” —-> +2.0 SD —-> 98% —-> 1 in 50
7.94” —-> +2.5 SD —-> 99.4% —-> 1 in 165
8.35” —-> +3.0 SD —-> 99.87% —-> 1 in 750

Judging from the rarity of 8”+, I’m guessing that these were NBP measurements. What kind of difference do you guys normally get between BP and NBP measurements? It’s a little over 1/2” for me.

Busted Bus

Yeah, 1/2” to 1” for the fat pad is typical. Those are useful breakdowns, thanks bustedbus!

Please :donatecar to Thunder's Place to keep it running.

Good stuff. Care to extend the table a few SDs either way, bus? hehe

Thinking about these things too much will make your head explode!

The more you read anecdotal stuff, the more you believe that standard deviations don’t apply to penis size.

The solution to all this confusion is to put the military in charge! The most complete data for normal, healthy human measurements (physical and mental) almost always comes from military sources. Height, weight, IQ etc.

They get 50,000 fresh faces every year and every one of them gets poked, prodded, and measured whether they like it or not. Somebody in the Pentagon decides that something is important and all the sudden every new recruit gets tested when they join. And it’s always done by legitimate medical personnel.

In fact, we could probably score millions of dollars for “Penis Enlargement Research”! We just have to convince a few generals that since a larger penis improves morale and self-esteem it only makes sense that we should find a way to give soldiers bigger units!

And then just think how successful the recruiting would be. Money for college is great, but get a slogan like “Join the Army, Get a 9 Inch Penis” and you’ll have every male in America over 16 trying to join!

Busted Bus

“Join the Army, Get a 9 Inch Penis”

You should put this in your signature. Too funny…

Please :donatecar to Thunder's Place to keep it running.

A whole bunch of averages:

Wikipedia says: “a mean erect human penis is approximately 12.9–15.0 cm (5.1–5.9 in) in length.” Nugteren, in a 2010 article from the Journal of Sex &Marital Therapy, “Experience in management of men with a complaint of a small penis” claims that the average size for white males is 4.92.” Michael Castleman, in a 2011 article from Psychology Today, “the rare truth about penis size” says that 95% of men fall into the 5-7” (erect) length. Men’s Health says 3” flaccid, 6” hard is about average and the Kinsey studies get 5-6.5” as their mean length from all the dicks the had men self-measure in the 40s and 50s. Durex condoms used the same self-measurement technique and came up with 6.4” as their average. Lifestyle, however, recruited nurses to go to a college keg party and measure young men’s penises and came out with 5.9” as their average. I got the condom stats from a wonderful movie My Penis and Everyone Else’s a 2007 documentary by Lawrence Barraclough a follow-up to his 2005 documentary, My Penis and I. One of those movies also talks about the bell curve graph and flashes it about too.

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