We present here a collection of the available studies about penis size. Most of this studies are performed by qualified stuff and include studies in which the measurements are actually done by the stuff and others in which the task is delegated to the subjects. All the studies are presented with a summary chart that includes the participant, the means and the standard deviation (in brackets when available).
Kinsey study (USA)
The Kinsey study was conducted in 1948 by the Kinsey Institute of Sex Research, and in it men were asked: “How long is your penis, measuring on the top side from your belly out to the tip?” They were each given a pre-stamped card to take home, and instructed to mark the length on the card when flaccid and when erect.
So the main concussion is that this is a self reported study that apparently takes the measure of the erect length Non Bone Pressed.
Self report studies tend to give higher averages, this study tries to minimize this bias by asking the subjects to mark in a card. Although this methodology seems better than just asking the participants is still a self reported study. We have considered the study since it is one of the biggest and most commented studies on penis size on the web.
Sources: Kinsey Institute, Gebhard, Paul, and Johnson, Alan. (1979/1998). The Kinsey Data: Marginal Tabulations of the 1938-1963 Interviews Conducted by the Institute for Sex Research (reprint edition). Bloomington, IN: Indiana University Press.
|Flaccid Length||9.0 (2,0)||3,5 (0,8)|
|Flaccid Girth||10.0 (0,75)||3,9 (0,3)|
|Stretched length||12,5 (2.5)||4,9 (1,0)|
Roberto Ponchietti et al. conducted this study in 1998 over 3300 Italian young men (17-19 years old) while screened in order to evaluate their attitude to serve in the army.
They took three measures: flaccid length, flaccid girth and stretched length. The flaccid circumference was taken at the middle of the shaft. All the measures were taken by the same physician.
This study is one of the biggest ones ever conducted and although it does not take any erect measures it is of great interest for flaccid statistics, which also worry many men in situations of public nudity such as locker rooms.
Source: Penile length and circumference: a study on 3300 young italian males. Ponchietti R. · Mondaini N. · Bonafè M. · Di Loro F. · Biscioni S. · Masieri L. Eur Urol 2001;39:183–186 (DOI:10.1159/000052434)
|Flaccid Length||8,95 (1,04)||3,5 (0,4)|
|Flaccid Girth||8,89 (0,86)||3,5 (0,3)|
|Stretched length||13,98 (1,58)||5,5 (0,6)|
The study was conducted in 2011 on 2276 young (mean 21.1 years old) Turkish men. It was then investigated if there was a relationship between the penis size and the hight, weight or Body Mass Index (BMI) of the participants.
Three measures were taken: flaccid length, flaccid girth and stretched length. The flaccid circumference was taken at the middle of the shaft. All the measures were taken by the same physician under similar environmental conditions (room light, air-conditioned room and at temperatures varying from 23 to 25ºC).
Weight and height were found to have a weak positive correlation with all penile measurements. Likewise, BMI was found to have a weak positive correlation with flaccid and circumferential lengths, but not with the stretched length.
Source: H Soylemez, M Atar, AA Sancaktutar, N Penbegul, Y Bozkurt and K Onem. Relationship between penile size and somatometric parameters in 2276 healthy young men. International Journal of Impotence Research (2012) 24, 126–129
|Erect Length||14,15 (2,66)||5,6 (1,0)|
|Erect Girth||12,23 (2,23)||4,8 (0,9)|
This study published in 2013 used the answers of 1661 men to an internet interview aiming to deliver custom size condoms for their use. For this purpose, had to download and print an erect penile measurement tool. The tool contained detailed, illustrated directions about how to measure their erect penis, from the underside base and choosing the letter or numerical code that is “closest to the end of the head of your penis”. While this methodology is not the usual one described in the measures section, it is intended to measure the penis up to the point a condom would unroll. This would correspond to a Non Bone Pressed measure, although measuring from the underside longer measurements can be easily obtained than from the upper side, which could explain why this study reports slightly longer erect penises than others done with the None Bone Pressed methodology.
The article does not mention where the circumference measurement is taken, although some other custom size condom companies take the measurement at the middle or at the base.
Although this study relies in self reported measurements, the wish of a fitted condom should motivate men to report their actual size specially for the circumference measurement, where the procedure is more standard. This together with the large sample makes this study quite interesting. Also, the authors mention that men with bigger and smaller penises could be more interesting in custom condoms, which could explain why the standard deviation is sensibly higher than in other studies.
|Flaccid Length||9,3 (1,3)||3,7 (0,5)|
|Stretched length||13,7 (1,6)||5,4 (0,6)|
1132 young Turkish men underwent measurements during military recruits between 2008 and 2009. The study aimed to look for correlation of penis size with high, weigh or BMI.
Two measures were taken: flaccid length and stretched length. All the measures were taken by the same physician under similar environmental conditions. The study also measured the testicular volume of the patients.
There was no correlation between the testicular volume and age, height, weight or BMI. A weak positive correlation between penile length and the mean testicular volume was observed. Also, weak positive correlations were found between penile length (flaccid and stretched) and height, weight and BMI. Neither flaccid nor stretched penile length had correlation with age.
Source: Yılmaz Aslan, Ali Atan, Ali Ömur Aydın, Varol Nalçacıoğlu, Altug Tuncel and Ateş Kadıoğlu. Penile length and somatometric parameters: a study in healthy young Turkish men. Asian Journal of Andrology (2011) 13, 339–341
|Subjects (N)||890 / |
|Flaccid Length||9,5 (1,7)||3,7 (0,7)|
|Flaccid Girth||8,8 (1,2)||3,5 (0,5)|
|Erect Length||[12.4 (1,4)]||[4.9 (0,6)]|
|Stretched length||12,7 (2,0)||5,0 (0.8)|
890 Venezuelan men were measured in 2001. 5 measures were taken: flaccid length, flaccid circumference (both at the base and at the glans), stretched length and the glans length. A sub-sample of 30 subjects underwent erect measurement too.
The teem found a correlation between height and penis size (p<0.01) as well as differences between ethnic groups. Among the 890 participants 42.5% were white (378), 41.1% were half-breed (366), 13.7% were black (122) and 2.7% of other ethnic groups (24). The measures according to ethnicity were as follows:
- Black: flaccid length: 10.2 (SD 1.7) cm, stretched length: 13.6 (2.1) cm.
- White: flaccid length: 9.4 (SD 1.6) cm, stretched length: 12.4 (1.9) cm.
- Half-breed: flaccid length: 9.3 (SD 1.6) cm, stretched length: 12.7 (1.8) cm.
- Other: flaccid length: 9.5 (SD 1.7) cm, stretched length: 12.7 (1.7) cm.
Among the sub-sample that underwent erect measurement it was also observed that the stretched length was strongly correlated with the erect length.
Mo Chung (Korea)
The study was made on 702 Korean male patients of the Department of Urology, Capital Military Hospital in 1971.
4 measurements were taken: flaccid length, flaccid circumference, erect length and erect circumference. The length measurements were taken from the symphysis pubis to the apex of the penis (i.e. Bone Pressed).
The study also found a slight correlation between the mean length and circumference of the penis.
Shahid Khan (GB)
|cm (SD)||inches (SD)|
|Flaccid Length||8,7 (1.6)||3,4 (0,6)|
|Stretched length||14,3 (1.7)||5,6 (0,7)|
Shahid Khan et al. conducted this study between 2007 and 2008 on 499 British (Scottish) patients undergoing routine examination in clinics and on 110 patients during examination under anesthetic. Making a total of 609 subjects.
Three measurements were taken: flaccid pendulous penile length, flaccid penobubic penile length (to the pubic arc, i.e. pressing the fat pad) and stretched flaccid penobubic length.
Apart from the results shown in the chart, the penopubic flaccid penile length was 10,2 cm with a standard deviation of 1,4 cm. The mean testicular volume was also measured, with a mean of 19,8 mL (SD 5,4 mL) for both the right and the left one.
Kwanjin Park (Korea)
|Flaccid Length||7,76 (1,19)||3,1 (0,5)|
|Flaccid Girth||9,02 (1,16)||3,6 (0,5)|
|Erect Length||14,06 (1,5)||5,5 (0,6)|
|Erect Girth||12,11 (1,10)||4,8 (0,4)|
|Stretched length||12,30 (1,33)||4,8 (0,5)|
In order to collect data to create a penile nomogram for the Korean male, 309 subjects were measured in 1998 both at flaccid and erect states to the nearest 0.5 cm by the same examiner. The erection was obtained by self-estimulation or with an injection of prostaglandin E1.
6 measurements were taken: flaccid length, flaccid circumference, fat pad depth, stretched length, erect length and erect circumference. The erect length was taken Non Bone Pressed, but the authors define a functional length as the sum of the erect length plus the fat pad depth, which is the one in the chart.
In addition to the measures shown in the chart, the Non Bone Pressed length was 11,88 (SD 1,32) cm and the fat pad depth was 2,25 (0,68) cm.
From March 11 to 17, 2001 a total 300 males over the age of 18 were measured, one at a time, by qualified medical staff in private tents at the Dady Rock nightclub in Cancun, Mexico during spring break.
The personnel measured the length and the circumference, the length was measured Bone Pressed but there is no information about where the circumference was measured.
Choi et al. conducted this study on 279 Korean men in 1999. This is a self reported study in which the participant where provided with a modified standardized self-measurement tool (paper tapes) designed for user convenience and to minimize measurement errors. Respondents were carefully instructed how to use the tapes. The distances between marks on the returned tapes were measured with a steel ruler to the nearest 1 mm.
The participants were asked to measure their erect length, presumably Non Bone Pressed due to the paper nature of the tape, and to take 3 different measurements of the circumference of their penises: at the base, at the shaft just below the shaft-glans junction and at the glans.
The circumference shown at the chart corresponds to the thickest part of the penis, which happened to be at the glans, the average circumference at the base was 11.28 cm and 10.75 below the glans.
|Flaccid Length||7,7 (1,3)||3,7 (0,5)|
|Erect Length||11,8 (1,5)||4,6 (0,6)|
|Stretched length||11,6 (1,4)||4,6 (0,5)|
|Flaccid Length||9,3 (1,9)||3,7 (0,75)|
|Flaccid Girth||8,9 (1,5)||3,5 (0,6)|
|Stretched length||13,5 (2,3)||5,3 (0,9)|
Awwad et al. conducted this study in 2004 with two groups of Jordanian patients, one of 271 patients attending urology clinic for reasons other than erectile dysfunction, and another of 109 patients attending Jordan specialized center for the treatment of erectile dysfunction.
Patients from group one were measured for flaccid length, midshaft flaccid circumference and stretched length. Patients from group two were measured for flaccid length, stretched length and erect length after trimex injection.
As it is shown in the charts, there is a noticeable difference between the flaccid and stretched lengths among the two groups, and given that there is no evidence relating impotency and penis size, this shows how studies with small samples can result in differing results.
Source: Z Awwad, M Abu-Hijleh, S Basri, N Shegam, M Murshidi and K Ajlouni. Penile measurements in normal adult Jordanians and in patients with erectile dysfunction. International Journal of Impotence Research (2005) 17, 191–195
The study took place in 2001, Turkey. 200 patients admited in the Department of Plastic and Reconstructive Surgery, Gülhane Military Medical Academy, Ankara, Turkey with any kind of symptom other than a genital disorder were included in this study. Measurements were made immediately after the patient as undressed to minimize the effect of temperature. Tape measurements of the penis were obtained to the nearest 0.5 cm by the same examiner.
The article explicitly mentions that the erect length “was measured from the penopubic junction to the tip of the penis in contrast to other studies that accepted the sum of the pubic fat depth and erect length”, so it means Non Bone Pressed. On the other hand, the stretched length is unusually short, which could be explained by different amount of pull than in other studies.
|Flaccid Length||8,26 (1,07)||3,25 (0,42)|
|Flaccid Girth||8,34 (1,03)||3,28 (0,41)|
|Erect Length||13,42 (1,38)||5,28 (0,54)|
|Erect Girth||11,17 (1,05)||4,40 (0,41)|
Conducten in 1998 in Korea over 150 subjects, this study aimed to see if there was a relation between penis size and stature, weight and BMI.
4 measurement were taken: flaccid length, flaccid circumference, erect length and erect circumference. The erect measurement method is not described in the abstract.
The article didn’t find any relations of penis size and any of the studied variables.
|Flaccid Length||8,95 (1,5)||3,52 (0,59)|
|Erect Length||13,90 (1,7)||5,47 (0,67)|
|Stretched length||13,60 (1,6)||5,35 (0,63)|
130 Caucasian men from Colombia underwent 4 measurements: flaccid length, Bone Pressed flaccid length, stretched length and Bone Pressed erect length.
The erection was achieved by an intracavernous drug.
In addition to the data shown in the chart the Bone Pressed flaccid length was 10.49 cm with a SD of 1.3 cm. And the ranges for the other measures were: [6, 13]cm for the flaccid length, [7, 13.5]cm for the Bone pressed flaccid, [10, 21]cm for the erection and [8.8, 19]cm for the stretched length.
|Flaccid Length||6,90 (0,8)||2,72 (0,3)|
|Flaccid Girth||8,50 (1,1)||3,35 (0,43)|
|Stretched length||9,6 (0,8)||3,78 (0,3)|
After an explanation and agreement to the purpose and methods of this study, 123 Korean men in their early 20’s visiting the Jinhae Military General Hospital were included in the study. The flaccid penile length, flaccid mid-shaft circumference, stretched length and pre-pubic bone fat pad depth were measured in a warm comfortable environment.
The study also asked the subjects to rate their penises as: “very small”, “small”, “normal”, “large” or “very large”.
In addition to the measurements shown in the chart, the average fat pad was 1.1cm (SD 0.4)
|Subjects (N)||111 (A)|
|Flaccid Length||8,60 (1,50)||3,39|
|Flaccid Girth||3,08 (0,40)||1,21|
|Erect Length||14,48 (1,99)||5,70|
|Erect Girth||3,95 (0,38)||1,56|
|Subjects (N)||32 (B)|
|Flaccid Length||9,22 (1,67)||3,63|
|Flaccid Girth||2,87 (0,31)||1,13|
|Erect Length||14,18 (1,83)||5,58|
|Erect Girth||3,50 (0,32)||1,38|
Shneider et al. conducted this study in 2000 in Germany. They measured two groups, one of 111 young men recruited by advertising in schools and another group of 32 older men that presented to their clinic because of erectile dysfunction.
The measures were taken by staff bone pressed, the erection was achieved by self stimulation for the A group and by an injection of prostaglandin E1 in the second group.
*The girth was measured as the diameter of the penis both at the base and the glans. The figures shown in the chart correspond to the ones at the base while the ones at the glans were 3,02 and 3,49 for the A group and 3,01 and 3,32 fot the B group.
The article also mentions the ranges of the measurement taken: flaccid length [5, 14,5], flaccid width at the base [2,0, 4,2], flaccid width at the glans [2,2, 3,7], erect length [10, 19], erect width at the base [2,7, 5,0] and erect width at the glans [2,5, 4,5].