Average size: some data

Discussion in 'Sex With a Large Penis' started by jhs1900, Mar 4, 2012.

  1. jhs1900

    jhs1900 New Member

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    I've transcribed these from a graph in the following publication:
    --------------------------------------------------------
    The Journal of Urology. Volume 156(3), September 1996, pp 995-997
    Penile Length in the Flaccid and Erect States: Guidelines for Penile Augmentation
    Wessells, Hunter; Lue, Tom F.; McAninch, Jack W.
    -----------------------------------------------------------

    They are nbp erect lengths in cms. The study was of 80 men, but on the graph there is simply a dot on each point - some of the dots clearly indicate more than one man (there are only 74 of them), but it's impossible to tell which.
    This is quite a well-known study, it found the average to be 12.89 with a s.d. of 2.91, but I thought it was interesting to see some more detail.


    7.5: 2
    8.0: 3
    8.5: 1
    9.0: 2
    9.5: 3
    10: 4
    10.5:4
    11: 4
    11.5:4
    12: 6
    12.5:5
    13: 4
    13.5: 3
    14: 5
    14.5: 4
    15: 1
    15.5: 3
    16: 5
    16.5: 2
    17: 2
    17.5: 1
    18: 3
    18.5: 0
    19: 3
     
  2. SteveT

    SteveT Active Member

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    Interesting. THanks for taking the time to print that all out! Interesting range there.
     
  3. B_handsomejack81

    B_handsomejack81 New Member

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    looks like a typical... bell-curve... distribution

    *chuckles to self*
     
  4. redbear52

    redbear52 New Member

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    More data from this study:

    Erect length is defined as from the pubo-penile skin to the meatus (NBPEL) (data above):
    mean 12.89 cm (5.07"), standard deviation 2.91 cm (1.15").

    Flaccid length (also measured from pubo-penile skin to meatus (NBPFL):
    mean 8.95 cm (3.52"), standard deviation 2.38 cm (.94")

    Fat pad depth: mean 2.85 cm (1.12"), standard deviation 1.59 cm (.63")

    Flaccid stretched length from pubo-penile skin to meatus (NBPFSL):
    mean 12.45 cm (4.90"), standard deviation 2.71 cm (1.07")

    Flaccid circumference at mid shaft:
    mean 9.71 cm (3.82"), standard deviation 1.17 cm (.46")

    Erect circumference at mid shaft:
    mean 12.30 cm (4.84"), standard deviation 1.31 cm (.52")

    Functional length (erect length plus fat pad depth or BPEL):
    mean 15.74 cm (6.20"), standard deviation 2.62 cm (1.03")

    This study does have quite a bit of variance (as indicated by the relatively large standard deviations for the length measurements compared to some others) and did include several rather large individuals since 3 of these 80 men had a NBPEL of 19 cm or greater (around 7.5" NBPEL) so the length results might in fact have been skewed a bit upward by chance.
     
  5. ShannonH

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    Where did you get the raw data from?
    I'd be interested in seeing if the 'fat pad depth' part applies evenly across all subjects, or if it skews to the smaller guys. Would those 3 7.5" all become 8.5"? Just looking at the distribution it seems more likely that those 6 guys around 3" erect are most likely just there because of fat-pad, since 2" of fat would account for that.

    Also, when and how is fat-pad measured? If they're measuring fat-pad separately and then just adding it to the NBPEL, they might be overestimating its effect.

    Oh and was it tape-measure, caliper, ruler, and would they measure 'with the curve'? I think the average would be significantly lower if they didn't.
     
  6. redbear52

    redbear52 New Member

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    The data comes from the publication, of course.

    They used tape measurements.

    "Tape measurements of the flaccid and erect penis were obtained to the nearest 0.5 cm by 1 examiner. Flaccid length, circumference, depth of the prepubic fat pad, and stretched penile length (fig. 1) were measured immediately after the patient undressed to minimize the effects of temperature. Measurements were made of the length from the pubo-penile skin junction to the meatus, circumference at the mid shaft, and fat pad depth by pushing the tape into the pubic bone. Stretched flaccid length was measured from the pubo-penile skin junction to the meatus under maximal extension of the phallus. All patients underwent intracavernous injection of prostaglandin E1 for evaluation of erectile dysfunction. After a period of privacy and self-stimulation, penile length and circumference were measured at full erection. If full rigidity was not obtained, a mixture of phentolamine, papaverine, and prostaglandin E1 was injected to enhance erection and measurements were repeated."

    The authors noted that "fat pad depth did not correlate with any parameter of penile size."

    The authors did compare fat pad depth, flaccid length, and stretched length in those subjects 40 years and younger, and those over the age of 40. Predictably, fat pad depth was significantly greater in the older group (3.06 cm vs. 1.77 cm, p=0.0058). While flaccid and stretched length was slightly less in the older group, the differences were not of statistical significance.
     
  7. ShannonH

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    I was hoping you had a URL for it somewhere. I've seen it on some medical paper sites but they charge for it.
     
  8. redbear52

    redbear52 New Member

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    I can't distribute the full text paper on this forum without a clear copyright infringement and I don't want to provide ammunition to those who would restrict internet access.

    However, if you go to this link:

    Penile length in the flaccid and erect states: guidelines for penile augmentation. | Mendeley

    and click on the scanned image icon in the upper right of the page, you can preview two pages, which represents the bulk of the article (2 out of 3 pages). The readability leaves a bit to be desired but I think you will be able to confirm the information given above.
     
  9. 3etr

    3etr Member

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    :3
     
  10. ShannonH

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    Thanks - looks like the 'functional length' was when they really push in to the fat pad, since they measured that with a tape measure. From what I can tell they measured that separately (ie erect length was measured NBP, then they measured the fat pad and just added that.) I've actually seen a lot of guys compare the most extremely bone-pressed measurement they have to the Wessells NBP result, and think they're above average since the average is only 5". Looking at the distribution, yes the 6.2" BPEL they get might be a bit higher since there is a drop-off after average then a sudden spike on the high side. Since they don't describe how they gathered these 80 patients it was probably on a volunteer basis which would explain that. I think if you're comparing at home, the only accurate way to do it against this is to just bone-press as hard as you can, then see how far from 6" you are.

    I'm guessing this is also where the 'the average penis is between 5 and 7 inches' comes from. If you take the BPEL, the standard deviation is about 1", so that's 6 +/- 1, or 5" to 7".

    Tape measure's good, since it implies measuring with the curve.

    One thing this study shows really well is the correlation between stretched and erect length -- the line of best fit is almost 1:1. What this means is that you can check your own erect length against the stretched length in any study. An individual may have a very different stretched vs. erect (one point that stands out is a guy who's about 5 1/4" stretched but almost 7" erect), but as a group it evens out so a set of a few hundred people's stretched measurement gives you the same data that a few hundred erect measurements do. I would say the stretched measurements would be more consistently accurate, since you don't have those variables like erection quality or curvature.
     
  11. ShannonH

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    Oh since I love numbers, I thought I'd do a cumulative % of each size. One thing that really stands out in this one vs the Lifestyles study (which is what mraverage.com uses) is that the smaller guys are better represented. If you go by lifestyles it looks like guys shorter than 4" are almost non-existant, but If you check the 8.5cm column (so after adding the fat pad are around 4") it looks like around 8% of guys are that short or shorter. That's far from a majority, but if you consider these are the 'medically normal' dicks, that's quite a lot more than I think most people would assume.
    cm n sum(n) %
    7.5 2 2 2.7027027027
    8 3 5 6.7567567568
    8.5 1 6 8.1081081081
    9 2 8 10.8108108108
    9.5 3 11 14.8648648649
    10 4 15 20.2702702703
    10.5 4 19 25.6756756757
    11 4 23 31.0810810811
    11.5 4 27 36.4864864865
    12 6 33 44.5945945946
    12.5 5 38 51.3513513514
    13 4 42 56.7567567568
    13.5 3 45 60.8108108108
    14 5 50 67.5675675676
    14.5 4 54 72.972972973
    15 1 55 74.3243243243
    15.5 3 58 78.3783783784
    16 5 63 85.1351351351
    16.5 2 65 87.8378378378
    17 2 67 90.5405405405
    17.5 1 68 91.8918918919
    18 3 71 95.9459459459
    18.5 0 71 95.9459459459
    19 3 74 100
     
  12. dirkjesje

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    Nice hack.
    It would be a real normal distribution - if the 7.5cm was only n=1, the 8cm n=2; and the 19cm n=1
    Strange that they have 3 of 19cm. ( +/- 7.5") [Probability is +/- 50% so yes - ok ]
     
  13. ShannonH

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    It's not that strange - if you want to get a more accurate picture on the tail ends, you need a larger sample set. It's only because there are only 74 in this set that 2 extra guys at 19cm makes it bump up that much.

    If we look at the Ponchietti study, they had 3000 subjects and did maximally stretched but non-bone-pressed measurements. They were military conscripts and young so they wouldn't have much of a fat pad, but it still lowers the measurement a bit. In Wessells, the fat-pad depth for <40 yrs averages at 1.8cm, so for 19 yrs I think 1-1.5cm is reasonable. Add that to the 99th percentile for Ponchietti (17.5cm) and you get to the same 19cm that they have. Ponchietti's larger sample size doesn't show a spike at that size. So looks like 19cm NBP (7.5") is about when a dick becomes extraordinarily large. This is true in both California and Italy.

    Of course, if 1/100 guys are 7.5"+, then there's still plenty of them out there. Modelling for art classes, starring in porn, and/or posting long analyses about dick statistics on LPSG when their brain could be put to better use elsewhere :)
     
  14. ShannonH

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    Oops, just noticed my math was backwards on the adding fat pad to the Ponchietti study bit, since those Wessels numbers are NBP. The median is almost identical in the two studies (12.5cm), but the Wessells numbers might be a little longer because they would be fatter. Still, just the fact that a different person was measuring can account for the slight differences so let's chalk it up to that.

    When you measure 74 guys in California and they're all around 12.5cm NBP, and you get the same thing on the other side of the world with 3000 Italians, you can be pretty confident in the number.
     
  15. B_mastersword

    B_mastersword New Member

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  16. jhs1900

    jhs1900 New Member

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    There's a new study in BJU International, Vol. 109 (5), pp. 740-744, which measures the stretched length of 609 British Caucasian men. I'm not a fan of using the stretched length as estimate for erect length, but here's what they found:

    using a rigid ruler, pressing to the bone, the mean stretched length was 14.3 cm, with an s.d. of 1.68 cm.

    The graphs they use aren't very clear, but it looks to me that at the top end there was 1 guy at 20-20.5, 2 at 19-19.5, 2 at 18.5-19, 7 at 18-18.5, and then back down to 2 at 17.5-18. So that's 14 guys - about 2.5% - at 7 inches or more.
     
  17. redbear52

    redbear52 New Member

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    Here is a link to a free abstract of that publication, for those who are interested: Establishing a reference range for penile length in Caucasian British men: a prospective study of 609 men - Khan - 2011 - BJU International - Wiley Online Library

    Pretty consistent with the results from the Ponchietti study which showed a mean stretched flaccid length of 12.5 cm when one considers that the Ponchietti study recorded non bone-pressed stretched flaccid length and this study recorded bone-pressed stretched flaccid length. The difference in the mean lengths of 1.8 cm (.7") would seem to be a reasonable estimate of average fat pad thickness in army recruits.

    This study's sample set showed considerably less variance than the Italian study, however, with a standard deviation of only 1.7 cm (.67") as opposed to an s.d of about 2.2 cm (.87").

    This much smaller study was done in 55 adult men being evaluated for ED: http://www.nature.com/ijir/journal/v12/n6/pdf/3900627a.pdf

    Bone-pressed stretched flaccid dorsal penis length and bone-pressed erect dorsal penis length after pharmacological induced erection in the same individuals. Mean bone-pressed stretched flaccid length was 12.5 cm (4.92") with a standard deviation of 1.4 cm (.55") but stretched flaccid length underestimated erect length by 1.1 cm (.43"). Mean bone-pressed erect length was 13.6 cm (5.35") with a s.d. of 1.7 cm (.67").
     
    #17 redbear52, Mar 11, 2012
    Last edited: Mar 11, 2012
  18. ShannonH

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    I think the italian study's higher SD might just be because they'd be including the extra SD of fat-pad, which probably varies by more than dick length. Considering how the results are almost never uniform (slope is much higher on the smaller side) it'd be great to just see a simple percentile breakdown rather than just infer from the deviations.

    What's really remarkable is not the measurements themselves, but by just how little these studies vary by when a consistent methodology is used. 14.5cm (about 5 3/4") for a median BPL has turned up in England, Brazil, Italy, and the US (students on spring break in the lifestyle's study.) Any one that includes multiple ethnicities has never found a difference between ethnic groups (I think maybe one showed a 0.2" difference with a 5% chance it was just a coincidence, which considering how many found no correlation it almost definitely was just a coincidence.) Compared to every other thing that varies by country/ethnic group (height, weight, incidence of diabetes, cancers, etc.) the consistency among dicks is surprising.
     
  19. B_handsomejack81

    B_handsomejack81 New Member

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    for any study to be taken seriously it cannot rely on self-measurement
     
  20. ShannonH

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    These ones don't. In fact every one quoted in this thread was taken by a professional.
     
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