Best statistical study for comparing at home

ShannonH

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Many have probably seen this already, but I came across what I think is easily the most repeatable measurement methodology if you want a reliable baseline. I think anyone who is asking questions here about where they fall statistically should check this one first.
http://www.scielo.br/pdf/jped/v83n5/en_v83n5a08.pdf

The sample size for 18-19 year olds (puberty complete) is about 160, so it's large enough to get a fair range. What I really like about it is that it goes in to specific detail about the one measurement methodology that doesn't have significant interobserver variation. That's the big problem with so many self-reported studies, or in comparing yourself to any study. I think a lot of people will use very forgiving measures on themselves (eg extreme bone-pressing) and then compare against a study that used a less-forgiving standard of measurement. People might compare against a study giving a 5.1" average and then conclude that they're huge, or compare against an internet study but round their own measurement down and conclude they're tiny.

This study finds that the only reliable, repeatable way to measure penis size is by RSLmax (real stretched length maximum.) They completely detail the methodology and even go as far as saying that different practitioners will get the same results and that just using a ruler is fine. The stretched-length is strongly correlated to erect length (in other words, if you have a long RSLmax then you almost certainly have a long erection.) This approach just stretches the penis as long as it will go, and presses the ruler down in to the fat pad, so the results are consistent.
The mean (ie average) which was 145mm +/- 14mm, or 5.7" with a standard deviation between 5.1" and 6.3", which is pretty much spot on with the highest averages and lowest averages studies have found.)
Most importantly it has percentile graphs so you can quickly see the percentile a measurement falls. 90th percentile is just under 170mm (6.7"), and 10th percentile is about 132mm (5.2").

What's really interesting is that the lower-percentiles are really closely grouped together, while the higher regions are pretty far apart. What that means is that even if you have a very low percentile, you'd only be half an inch shorter than the average. However, there's a wider range of big dicks out there. It really kind of points out how few noticeably small guys (free of medical abnormalities) there really are out there.

So go ahead, stretch that thing as far as it will go, push that ruler in, and know that you're doing it the right way and not just fooling yourself :)
 

dirkjesje

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Well I tried this method just now by strechting as much as it will go.
I got 165mm (6"50), while I'm NBPL 175mm (6"75).
As I'm no grower, but rather a shower, this method seems to me not the best way to measure the penis lenght.
I'm limp always 5" or more, even with my feet in ice cold water no less than 4".
So I think that showers like me will have an advantage by this strechting method of measuring.
 

henry8888

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Well i hadnt finished puberty at 19 and lots of others wont have either, and my cock has grown alot since then (in thickness).
Also if i use their measuring technique it measures 3/4 of an inch shorter than when i measure it erect.
 

D_Bubba_Butter

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Dirkjesje - this is actually the most reliable way of comparing, as it stretches the penis and suspensory ligament to the limit of the elastic tissues & takes the fat pad out of the equation.

Being a grower or a shower therefore doesn't make any difference to the results with this technique.
 

D_JuanAFock

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Dirkjesje - this is actually the most reliable way of comparing, as it stretches the penis and suspensory ligament to the limit of the elastic tissues & takes the fat pad out of the equation.

Being a grower or a shower therefore doesn't make any difference to the results with this technique.
I was able to extend out to a little over 6.25" with this method (different room temps though, dunno how much that effects the measurement), I am a grower (~3.5" flaccid, depending on temperature of course). Could be a good way to find max length at least.

EDIT: It is strange though, because it seems like I am still growing... I swear 2 years ago I was barely 6".
 
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dirkjesje

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Dirkjesje - this is actually the most reliable way of comparing, as it stretches the penis and suspensory ligament to the limit of the elastic tissues & takes the fat pad out of the equation.

Being a grower or a shower therefore doesn't make any difference to the results with this technique.
Well it does.
My penis doesn t grow so much. It is limp almost the same as erected. ( grows about +/-25%) So mine is easy to strech. I have almost no fat pad - NPBL and BPL is about the same ( less than 1cm difference ).

As I have a high body temperature ( from birth ), between 37.8 and 38.0 Celsius (normal) - and even at 38.4 I dont have fever, my penis easily stretch. I saw several men in sauna and nudist beachs, well I don t know how they can stretch them to 6" as they are mostly the half of me limp.

I stay with the "discussed" non bone pressed lenght.
Measuring - standing up - erected - holding the penis as much parallel to the floor (horizontal) - measuring on top - from pubis to tip, without pressure. (visible lenght - and also for condoms the needed lenght - cfr Durex)
 

D_Bubba_Butter

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Well, if that works for you. Erect is usually slightly shorter than RSLmax because filling out the corpora restricts stretch lengthways (i.e. you can stretch an empty balloon further lengthways than one filled with water) & the suspensory ligament also has an effect.

& bigloadz:

EDIT: It is strange though, because it seems like I am still growing... I swear 2 years ago I was barely 6".

Lucky you! I stopped growing when I was about 14. Wish I'd kept going at the same rate for a few more years. :( Still, reckon what I've got ain't bad. :)
 
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dirkjesje

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Well, if that works for you. Erect is usually slightly shorter than RSLmax because filling out the corpora restricts stretch lengthways (i.e. you can stretch an empty balloon further lengthways than one filled with water) & the suspensory ligament also has an effect.
Well then I need more info. RSLmax > erect?
Not in my case. Or I didn t do the correct method.
RSLmax was 6"50 ; Erected NPBL 6"75
 

redbear52

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I have seen this study before. I credit the authors for giving a thorough explanation of their methodology. This has not been the case with a number of surveys.

Not all have agreed that stretched flaccid length is a good indicator of erect length. Some studies have found a high correlation, but others have found that stretched flaccid length tends to significantly underestimate erect length. Furthermore, in some individuals, the fully stretched flaccid length will be less than the erect length. It seems to be the case that in a lot of guys who do PE the stretched flaccid length is longer than the erect length, typically by about 1/2" or so.

To give an example of why I'm not sure that bone-pressed flaccid stretched length is a good indicator of bone-pressed erect length, consider my example. I have a bone-pressed erect length of right around 8" but I can relatively easily achieve a bone pressed stretched flaccid length of 8.5", more if I stretch really hard. 8.5" corresponds to 216mm. That would put my RSL max at 71mm above the average for 18 yr olds. That is 4.4 standard deviations above the mean. If the RSL max closely predicted erect length, it 4.4 SD above the mean would suggest that I was well above the 99th percentile in length.

While I am a healthy bit above average, I certainly am nowhere close to the 99+ percentile.
 

D_Tess_Tease

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yep,
worked for me too, 7.5 RSL. usually im 7 hard but the other day I got a 'super hardon' and with my cockring on I measured 7.5. must have been holding a bit of extra blood in the shaft eh?

Bill
 

D_Bubba_Butter

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Only marginally, but there's not a perfect correlation between erect & RSLmax. The data showing how the two relate is usually shown as a scatter plot with line of best fit... You might just be someone who doesn't fit the rule. But it's independent of grower/shower status.
 

dirkjesje

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I have seen this study before. I credit the authors for giving a thorough explanation of their methodology. This has not been the case with a number of surveys.

Not all have agreed that stretched flaccid length is a good indicator of erect length. Some studies have found a high correlation, but others have found that stretched flaccid length tends to significantly underestimate erect length. Furthermore, in some individuals, the fully stretched flaccid length will be less than the erect length. It seems to be the case that in a lot of guys who do PE the stretched flaccid length is longer than the erect length, typically by about 1/2" or so.

To give an example of why I'm not sure that bone-pressed flaccid stretched length is a good indicator of bone-pressed erect length, consider my example. I have a bone-pressed erect length of right around 8" but I can relatively easily achieve a bone pressed stretched flaccid length of 8.5", more if I stretch really hard. 8.5" corresponds to 216mm. That would put my RSL max at 71mm above the average for 18 yr olds. That is 4.4 standard deviations above the mean. If the RSL max closely predicted erect length, it 4.4 SD above the mean would suggest that I was well above the 99th percentile in length.

While I am a healthy bit above average, I certainly am nowhere close to the 99+ percentile.
What I don t understand is that you can have a longer stretched flaccid lenght -> erected bone pressed lenght.
I must doing something wrong with my previous and first measurement.

But I think you are also a shower like me, and easily to stretch...
 

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I measured myself this way. And BP and NBP.

My observations are:
1. I can lose some fat pad. Difference between NBEL and BPEL = 1.5 cm = 0.6 inch
2. I am a grower. NBSL (S=soft) = 10 cm = 4 inch; BPSL = 12 cm = 4.7 inch
3. RSLmax > BPEL. RSLmax I measured an exact 8 inches (20.3 cm), while BPEL I am 19 cm = 7.5 inch. I measured myself before at 18.5 and 19 cm.

Therefore my conclusion would be that you can stretch more when you are thicker (like me). Makes sense, as there is more to stretch .. :wink: Unfortunately that conclusion is already rejected by dirkjesje's results, as he isn't thin either, but is smaller when measuring RSLmax.
 

ShannonH

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Your RSLmax in the study won't always equal your EL, but they're usually pretty close. As has been pointed out there's a line of best fit that shows them to be pretty close, so if your erect varies significantly from your stretched, it might not be as useful, but it still gives a very accurate impression of the distribution.
The most important part is that it's the most consistently reproduceable method. It might not be perfect for every individual (works for many but not all) but it does keep everyone honest (a rare occurrence when dealing with this subject.)

Another example of where it's a bad idea to project individual experience on to an aggregate study is in saying something like 'I was still developing at 18' or some such. That might be sort of true for you, but this study had trained doctors specifically looking at their subjects development and by 18 they could say (as shown in their Taylor index) that the vast majority had completed puberty. You'll also notice that the line starts to flatten sharply around that age. Maybe not every single person ever is done growing at that point, but there's no way the median and percentile points will change significantly after that. I don't know how much you expect things to change or what that implies -- it's silly to think you could compare and say 'yeah I'm pretty big compared to your average 19 year old, but I'm small compared to men at 25'. I don't think the change in those years could even be greater than experimental error.

Oh and to Redbear's comment - if those are accurate measurements, how are you sure you're not in the 99th+ percentile? 99% sounds like a lot on an English exam, but 99th percentile is only 1 in 100 rare, which yeah is longer than a big (heh) majority, but being 1 in 100 rare on anything isn't that unusual that it seems absurd. For some perspective, I think an american man at the 99th percentile for height would be around 6'5 - yes tall but we all know someone that tall or more, and a little shorter than most NBA players. Just based on what has turned up in the 'measured porn stars' thread I don't really think it's all that far fetched.
 

quantaviusK

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Bump, as i just referenced this thread in another ;) Oh and I measured in at 215 mm, then measured my erection at 201mm. Dont those with foreskin have an unfair advantage when measuring RSLmax?
 

ShannonH

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Wait, are people measuring their foreskins? Don't measure your foreskin!
It's base of the penis to tip of the glans. Roll the foreskin back. I know guys will try to measure whatever makes it seem the biggest, but if you're measuring foreskin then you might as well just yank your longest pube out as far as it will go and count that.
 

drabman

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I have seen this study before. I credit the authors for giving a thorough explanation of their methodology. This has not been the case with a number of surveys.

Not all have agreed that stretched flaccid length is a good indicator of erect length. Some studies have found a high correlation, but others have found that stretched flaccid length tends to significantly underestimate erect length. Furthermore, in some individuals, the fully stretched flaccid length will be less than the erect length. It seems to be the case that in a lot of guys who do PE the stretched flaccid length is longer than the erect length, typically by about 1/2" or so.

To give an example of why I'm not sure that bone-pressed flaccid stretched length is a good indicator of bone-pressed erect length, consider my example. I have a bone-pressed erect length of right around 8" but I can relatively easily achieve a bone pressed stretched flaccid length of 8.5", more if I stretch really hard. 8.5" corresponds to 216mm. That would put my RSL max at 71mm above the average for 18 yr olds. That is 4.4 standard deviations above the mean. If the RSL max closely predicted erect length, it 4.4 SD above the mean would suggest that I was well above the 99th percentile in length.

While I am a healthy bit above average, I certainly am nowhere close to the 99+ percentile.

I agree with most of your post, except for the last part. IIRC correctly 8" BPEL is in fact close to 99th percentile. I believe its bang on in many surveys, for example Lifestyles. I've seen a survey that didn't even even find one penis longer than that in BPFSL, so that size is fairly rare according to most surveys.
 

drabman

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Bump, as i just referenced this thread in another ;) Oh and I measured in at 215 mm, then measured my erection at 201mm. Dont those with foreskin have an unfair advantage when measuring RSLmax?

That's around 9", yet in your gallery you claim 7.5" or thereabouts.

???