calcSD

Penis Percentile Calculator

The calcSD Average (v3)

This page is outdated, for the new version of the calcSD Average, please go here.

Sometimes we change so many things that we need a page just talking about all the changes. This page details the calcSD Average, how it was achieved and what composes it. If you're looking for the previous version of the calcSD Average, it's still available here.


This page highlights the studies that were used to create the calcSD Global Average v3, how they were chosen and how an average is calculated from all the data they provide.


Gathering More Studies

Searching for new studies is more convoluted than it should be. Firstly, most articles are hidden behind a paywall, which is fine until they decide to leave out important information from the abstract, like the measuring method or the standard deviation. Secondly, trying to gather that data by other means is a tedious process of looking through many pages, images and tables and hoping that one of the people that made them was generous enough to put the necessary info there.

Thankfully, /u/FrigidShadow has compiled the data of a vast number of these studies to form the new calcSD Average. If there's anything we've overlooked, or if there are more reliable studies to include or something wrong in any of the ones that we've included, please feel free to contact us about it.


Unlike most other iterations of averages, this utilizes a weighting that is 50% weighted by sample size and 50% weighted equally to each study. The rationale for this is that studies with larger sample sizes have a lower margin of error and should therefore be weighted more than lower sample size studies, however they do not have any improvement to potential biases. If solely weighted by sample size, a study with thousands of men sampled would effectively make negligible other studies of only hundreds of individuals. This would bias the resulting average in favor of individual studies with biases that may not accurately reflect the general population. So to reduce the risk of skewing the results towards the biases of a small portion of studies with very large sample sizes, the weighting is cut halfway towards uniform weighting of each study.

Additionally, to make this average more representative of the general adult population, we have excluded:


Currently, the average includes a total of 41 studies:

Study Avg. BP Erect Length (SD) Avg. NBP Erect Length (SD) Avg. Erect Girth (SD) Avg. Flaccid Girth (SD) Avg. BP Flaccid Length (SD) Avg. NBP Flaccid Length (SD) Avg. BP Stretched Length (SD) Avg. NBP Stretched Length (SD)
Acuña et al. 1999 13.90cm (1.70) 5.47" (0.67) N/D N/D N/D N/D N/D N/D 10.49cm (1.30) 4.13" (0.51) 8.95cm (1.50) 3.52" (0.59) 13.60cm (1.60) 5.35" (0.63) N/D N/D
Ajmani et al. 1985 N/D N/D N/D N/D N/D N/D 8.87cm (0.97) 3.49" (0.38) N/D N/D 8.26cm (1.52) 3.25" (0.60) N/D N/D N/D N/D
Aslan et al. 2011 N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D 9.30cm (1.30) 3.66" (0.51) N/D N/D 13.70cm (1.60) 5.39" (0.63)
Awwad et al. 2005 Group 1 N/D N/D N/D N/D N/D N/D 8.98cm (1.50) 3.54" (0.59) 9.30cm (1.90) 3.66" (0.75) N/D N/D 13.50cm (2.30) 5.31" (0.91) N/D N/D
Barboza et al. 2018 N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D 16.06cm (1.64) 6.32" (0.64) N/D N/D
Chaurasia & Singh 1974 N/D N/D N/D N/D N/D N/D 8.77cm (0.70) 3.45" (0.28) N/D N/D 7.36cm (0.77) 2.90" (0.30) N/D N/D N/D N/D
Chen et al. 2000 13.60cm (1.70) 5.35" (0.67) N/D N/D 10.90cm (1.60) 4.29" (0.63) 8.10cm (1.50) 3.19" (0.59) 8.30cm (1.30) 3.27" (0.51) N/D N/D 12.50cm (1.40) 4.92" (0.55) N/D N/D
Chen et al. 2014 12.90cm (1.30) 5.08" (0.51) N/D N/D 10.50cm (0.90) 4.13" (0.35) 8.00cm (0.80) 3.15" (0.31) N/D N/D 6.50cm (0.70) 2.56" (0.28) 12.90cm (1.20) 5.08" (0.47) N/D N/D
Choi et al. 2011 N/D N/D N/D N/D N/D N/D N/D N/D 7.70cm (1.70) 3.03" (0.67) N/D N/D 11.70cm (1.90) 4.61" (0.75) N/D N/D
Eisenberg et al. 2012 N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D 12.54cm (2.03) 4.94" (0.80) N/D N/D
Farkas 1971 N/D N/D N/D N/D N/D N/D 9.57cm (0.83) 3.77" (0.33) N/D N/D 7.22cm (1.12) 2.84" (0.44) N/D N/D N/D N/D
Foresta et al. 2018 N/D N/D N/D N/D N/D N/D 9.40cm (1.10) 3.70" (0.43) 8.90cm (1.70) 3.50" (0.67) N/D N/D N/D N/D N/D N/D
Gabrich et al. 2007 N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D 14.50cm (1.60) 5.71" (0.63) N/D N/D
Habous et al. 2015[1] 14.34cm (1.86) 5.65" (0.73) 12.53cm (1.93) 4.93" (0.76) 11.50cm (1.74) 4.53" (0.69) N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D
Habous et al. 2015[2] 14.30cm (2.00) 5.63" (0.79) N/D N/D 11.60cm (1.50) 4.57" (0.59) 9.40cm (1.50) 3.70" (0.59) N/D N/D N/D N/D 11.7cm (1.60) 4.61" (0.63) N/D N/D
Hussein et al. 2017 N/D N/D N/D N/D N/D N/D N/D N/D 9.80cm (2.00) 3.86" (0.79) N/D N/D 12.6cm (1.90) 4.96" (0.75) N/D N/D
Khan et al. 2012 N/D N/D N/D N/D N/D N/D N/D N/D 10.20cm (1.40) 4.02" (0.55) 8.70cm (1.56) 3.43" (0.61) 14.30cm (1.68) 5.63" (0.66) N/D N/D
Mehraban et al. 2006 N/D N/D N/D N/D N/D N/D 8.66cm (1.01) 3.41" (0.40) N/D N/D N/D N/D N/D N/D 11.58cm (1.42) 4.56" (0.56)
Motofumi et al. 2012 N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D 9.41cm (1.54) 3.70" (0.61) N/D N/D 12.22cm (1.72) 4.81" (0.68)
Nasar et al. 2011 N/D N/D N/D N/D N/D N/D 10.48cm (0.69) 4.13" (0.27) N/D N/D 8.37cm (1.31) 3.30" (0.52) N/D N/D N/D N/D
Park et al. 1998 14.06cm (1.49) 5.54" (0.59) 11.88cm (1.32) 4.68" (0.52) 12.11cm (1.10) 4.77" (0.43) 9.02cm (1.16) 3.55" (0.46) N/D N/D 7.76cm (1.19) 3.06" (0.47) N/D N/D 12.3cm (1.33) 4.84" (0.52)
Pereira 2004 15.85cm (2.11) 6.24" (0.83) N/D N/D N/D N/D 9.39cm (1.05) 3.70" (0.41) 9.86cm (1.84) 3.88" (0.72) N/D N/D 15.14cm (2.12) 5.96" (0.83) N/D N/D
Promodu et al. 2007 Group 3 N/D N/D 12.93cm (1.63) 5.09" (0.64) 11.49cm (1.04) 4.52" (0.41) N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D
Salama 2015[1] Control 15.00cm (1.80) 5.91" (0.71) 13.00cm (1.70) 5.12" (0.67) 11.80cm (1.00) 4.65" (0.39) 8.98cm (0.90) 3.54" (0.35) 10.02cm (1.90) 3.94" (0.75) 8.05cm (1.80) 3.17" (0.71) N/D N/D N/D N/D
Salama 2015[2] Control 15.04cm (1.51) 5.92" (0.59) 10.00cm (1.56) 3.94" (0.61) 11.92cm (1.06) 4.69" (0.42) 9.14cm (0.89) 3.60" (0.35) 12.88cm (1.46) 5.07" (0.57) 7.81cm (1.31) 3.07" (0.52) N/D N/D N/D N/D
Schneider et al. 2001 Group A 14.48cm (1.99) 5.70" (0.78) N/D N/D N/D N/D N/D N/D 8.60cm (1.50) 3.39" (0.59) N/D N/D N/D N/D N/D N/D
Shalaby et al. 2014 N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D 13.84cm (1.35) 5.45" (0.53)
Sengezer et al. 2002 N/D N/D 12.73cm (1.40) 5.01" (0.55) N/D N/D N/D N/D N/D N/D 6.80cm (0.54) 2.68" (0.21) N/D N/D 8.98cm (0.81) 3.54" (0.32)
Siminoski et al. 1993 N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D 9.40cm (1.4) 3.70" (0.55)
Son 1999 11.90cm (1.30) 4.69" (0.51) 10.80cm (1.30) 4.25" (0.51) 11.30cm (1.2) 4.45" (0.47) 8.90cm (0.80) 3.50" (0.31) N/D N/D 6.10cm (1.30) 2.40" (0.51) N/D N/D 9.60cm (1.20) 3.78" (0.47)
Son et al. 2003 N/D N/D N/D N/D N/D N/D 8.50cm (1.10) 3.35" (0.43) N/D N/D 6.90cm (0.80) 2.72" (0.31) N/D N/D 9.80cm (0.80) 3.86" (0.31)
Soylemez et al. 2011 N/D N/D N/D N/D N/D N/D 8.89cm (0.86) 3.50" (0.34) 8.95cm (1.04) 3.52" (0.41) N/D N/D 13.98cm (1.58) 5.50" (0.62) N/D N/D
Spyropoulos et al. 2002 N/D N/D N/D N/D N/D N/D 8.60cm (1.06) 3.39" (0.42) N/D N/D N/D N/D N/D N/D 12.18cm (1.70) 4.80" (0.67)
Stewart et al. 2009 N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D 15.00cm (1.70) 5.91" (0.67) N/D N/D
Vasconcelos et al. 2012 N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D N/D 16.00cm (1.90) 6.30" (0.75) N/D N/D
Wessells et al. 1996 15.74cm (2.62) 6.20" (1.03) 12.89cm (2.91) 5.07" (1.15) 12.30cm (1.31) 4.84" (0.52) 9.71cm (1.17) 3.82" (0.46) N/D N/D 8.85cm (2.38) 3.48" (0.94) N/D N/D 12.45cm (2.71) 4.90" (1.07)
Wu et al. 1990 N/D N/D N/D N/D N/D N/D N/D N/D 7.92cm (1.04) 3.12" (0.41) 6.62cm (1.02) 2.60" (0.40) 13.90cm (1.13) 5.47" (0.44) N/D N/D
Wu et al. 1994 N/D N/D N/D N/D N/D N/D 8.21cm (0.60) 3.23" (0.24) 7.41cm (0.95) 2.92" (0.37) N/D N/D 13.41cm (1.13) 5.28" (0.44) N/D N/D
Wu & Yang 1993 13.51cm (1.08) 5.32" (0.43) N/D N/D 11.03cm (0.83) 4.34" (0.33) 8.48cm (0.76) 3.34" (0.30) 8.04cm (1.10) 3.17" (0.43) 6.91cm (1.16) 2.72" (0.46) 13.81cm (1.15) 5.46" (0.45) N/D N/D
Yafi et al. 2018 13.73cm (1.90) 5.41" (0.75) N/D N/D N/D N/D N/D N/D 10.03cm (1.73) 3.95" (0.68) N/D N/D 14.00cm (1.83) 5.51" (0.72) N/D N/D
Yoon et al. 1998 N/D N/D 13.42cm (1.38) 5.28" (0.54) 11.17cm (1.05) 4.40" (0.41) 8.34cm (1.03) 3.28" (0.41) N/D N/D 8.26cm (1.07) 3.25" (0.42) N/D N/D N/D N/D
calcSD Global Average 14.11cm (1.73) 5.55" (0.68) 12.26cm (1.68) 4.83" (0.66) 11.46cm (1.26) 4.51" (0.50) 8.79cm (0.93) 3.46" (0.37) 9.09cm (1.40) 3.58" (0.55) 7.61cm (1.13) 3.00" (0.44) 13.64cm (1.54) 5.37" (0.61) 12.04cm (1.44) 4.74" (0.57)
Number of people: 2819 1878 2334 14770 7331 10185 12475 6046
BP Erect Length NBP Erect Length Erect Girth Flaccid Girth BP Flaccid Length NBP Flaccid Length BP Stretched Length NBP Stretched Length

Last updated: Sep. 17, 2019 (calcSD v2.0.1)