Sources: Every Study Behind Our Numbers
The clinical baseline, every verified national study with sample size and method, and the research behind our guides. Clinician-measured data comes first.
How we choose sources
- Studies where researchers or clinicians did the measuring always come before self-reports.
- Self-measured or self-reported data is labeled as such, because it tends to run high.
- Every study listed here was checked against its published abstract or record: sample size, method and values.
- Where we don't have a verified study, we say so instead of filling the gap with a weak source.
The baseline: Veale et al. 2015
Every percentile on this site is calculated against the largest systematic review of clinically measured men, with up to 15,521 men. It only included studies where a health professional measured with a standard procedure and at least 50 men took part, so self-measurements don't count.
Erect length
13.12 cm SD 1.66
Erect girth
11.66 cm SD 1.10
Flaccid length
9.16 cm SD 1.57
Flaccid girth
9.31 cm SD 0.90
Veale D, et al. Am I normal? A systematic review and construction of nomograms for flaccid and erect penis length and circumference in up to 15 521 men. BJU Int. 2015;115(6):978–986.
National studies (13 studies, 12 countries)
These are shown on each country page for transparency. The country rankings, the map and the comparisons keep using one aggregated dataset so that all 134 countries stay comparable.
Bangladesh
stretched 11.21 cm · flaccid 7.81 cm
n = 300, adult hospital patientsMeasured by researchers
Mallik AU, Rahman MM, Karmaker U, et al. Reference range of penile dimensions of the adult male and correlation with somatometric parameter in a tertiary care hospital of Bangladesh. KYAMC J. 2021;12(3):122–126. Source
China
erect length 12.90 cm · erect girth 10.50 cm · stretched 12.90 cm
n = 311, erect subgroup of 5,196 menMeasured by researchers
Chen X, Li R, Yang H, Dai J. A comprehensive, prospective study of penile dimensions in Chinese men of multiple ethnicities. Int J Impot Res. 2014;26:172–176. Source
Colombia
erect length 13.90 cm · stretched 13.68 cm
n = 130, Bogotá, men with erectile dysfunction, not representativeClinician-measured, induced erection
Acuña Cañas A, Villalba JC. Estudio antropométrico del pene. Urol Colomb. 1999;8(2). Source
Germany
erect length 14.48 cm
n = 111, aged 18–19Measured by researchers
Schneider T, Sperling H, Lümmen G, Syllwasschy J, Rübben H. Does penile size in younger men cause problems in condom use? A prospective measurement of penile dimensions in 111 young and 32 older men. Urology. 2001;57(2):314–318. Source
India
erect length 13.01 cm · erect girth 11.46 cm
n = 93, erect subgroup, KeralaMeasured by researchers
Promodu K, Shanmughadas KV, Bhat S, Nair KR. Penile length and circumference: an Indian study. Int J Impot Res. 2007;19(6):558–563. Source
Iran
stretched 12.22 cm · flaccid 7.87 cm
n = 500, soldiers in Tehran, measured by urologistsMeasured by researchers
Mohseni Rad H. Penile length: a study in Iranian military soldiers. J Res Urol. 2019;3(2):33–40. Source
Italy
stretched 12.50 cm · flaccid 9.00 cm
n = 3,300, young men aged 17–19Measured by researchers
Ponchietti R, Mondaini N, Bonafè M, et al. Penile length and circumference: a study on 3,300 young Italian males. Eur Urol. 2001;39(2):183–186. Source
Mexico
stretched 10.90 cm · flaccid 8.70 cm
n = 150, Mexico City, measured by urologistsMeasured by researchers
Carrillo-Córdova LD, Calvo-Mena D, Camilo-Martínez EJ, et al. Correlación entre medidas antropométricas y peneanas en la población mexicana. Rev Mex Urol. 2018;78(4):254–262. Source
Saudi Arabia
erect length 14.34 cm · erect girth 11.50 cm
n = 778, urology outpatientsClinician-measured, induced erection
Habous M, Tealab A, Williamson B, et al. Erect penile dimensions in a cohort of 778 Middle Eastern men: establishment of a nomogram. J Sex Med. 2015;12(6):1402–1406. Source
South Korea
erect length 13.42 cm · erect girth 11.17 cm · flaccid 8.26 cm
n = 150, university studentsMeasured by researchers
The relationship between height and body weight and penile size in university students. Korean J Urol. 1998:1061–1064. Source
Turkey
stretched 13.98 cm · flaccid 8.95 cm
n = 2,276, healthy young menMeasured by researchers
Söylemez H, Atar M, Sancaktutar AA, Penbegül N, Bozkurt Y, Önem K. Relationship between penile size and somatometric parameters in 2276 healthy young men. Int J Impot Res. 2012;24(3). Source
United States
erect length 12.90 cm
n = 80Clinician-measured, induced erection
Wessells H, Lue TF, McAninch JW. Penile length in the flaccid and erect states: guidelines for penile augmentation. J Urol. 1996;156(3):995–997. Source
erect length 14.15 cm · erect girth 12.23 cm
n = 1,661Self-measured, tends to run high
Herbenick D, Reece M, Schick V, Sanders SA. Erect penile length and circumference dimensions of 1,661 sexually active men in the United States. J Sex Med. 2014;11(1):93–101. Source
The country averages
The headline figure on each country page comes from public aggregators such as WorldData.info. They mix clinician-measured studies with self-reported surveys of very different quality, and for most countries the individual sources can't be verified. That's why every country page carries a data quality rating, and why we never use these figures as the baseline for your percentile.
Research behind our guides
What partners think
- Lever J, Frederick DA, Peplau LA. Does size matter? Men's and women's views on penis size across the lifespan. Psychology of Men & Masculinity, 2006.
- Prause N, Park J, Leung S, Miller G. Women's preferences for penis size: a new research method using selection among 3D models. PLoS ONE, 2015.
- Francken AB, et al. What importance do women attribute to the size of the penis? European Urology, 2002.
Condom fit
- Crosby RA, Yarber WL, Graham CA, Sanders SA. Does it fit okay? Problems with condom use as a function of self-reported poor fit. Sex Transm Infect. 2010;86(1):36–38.
- Reece M, Herbenick D, Dodge B. Experiences of condom fit and feel among African-American men who have sex with men. Sex Transm Infect. 2007;83(6):454.
Is the average changing?
- Belladelli F, Del Giudice F, Glover F, et al. Worldwide temporal trends in penile length: a systematic review and meta-analysis. World J Mens Health. 2023;41(4):848–860.
Body and height
- Mautz BS, Wong BBM, Peters RA, Jennions MD. Penis size interacts with body shape and height to influence male attractiveness. PNAS, 2013.
- Shah J, Christopher N. Can shoe size predict penile length? BJU International, 2002.
Erections and lasting longer
- Waldinger MD, et al. A multinational population survey of intravaginal ejaculation latency time. J Sex Med, 2005.
- Althof SE, et al. International Society for Sexual Medicine (ISSM) definition of premature ejaculation. J Sex Med, 2014.
- Feldman HA, et al. Impotence and its medical and psychosocial correlates: results of the Massachusetts Male Aging Study. J Urol, 1994.
- Capogrosso P, et al. One patient out of four with newly diagnosed erectile dysfunction is a young man. J Sex Med, 2013.
Enlargement
- Gontero P, et al. A pilot phase-II prospective study to test the efficacy and complications of a penile extender in the treatment of short penis. BJU International, 2009.
- Oderda M, Gontero P. Non-invasive methods of penile lengthening: fact or fiction? BJU International, 2011.
Found a mistake or a better study?
Write to info@malesizeindex.com. We check every suggestion against the original paper. How we handle corrections is described in our editorial policy.
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