One factor that is quite dominant in determining the normal penis size is genetic factor. This is an important factor which must be different from every race, heredity, and state as a whole. Diet and lifestyle from generation to generation forming the root of genetic makeup of a races in various countries.
As the results, specifically, every race and nation have no similar size of the penis during erection.
Here is an average penis size during erection worldwide of countries based on several sources from longest to shortest in the men aged 26 to 40 years.
1. Congo
An average penis size during erection: 7.1 inches (17.93 cm).
Source: l’Universite Kongo / Mbanza-Luvaka.
2. Ecuador
An average penis size during erection: 6.9 inches (17.59 cm).
Source: Infra. Dr. Cesar Cabezas Tamayo Guayaquil, 2006.
3. Ghana
An average penis size during erection: 6.8 inches (17.31 cm).
Source: Noguchi Memorial Institute for Medical Research (NMIMR).
4. Colombia
An average penis size during erection: 6.7 inches (17.03 cm).
Source: Acuna A, Villalbe J. & Juan Carlos Denoy, Clinica A. Saio, Bogota.
5. Venezuela
An average penis size during erection: 6.7 inches (16.93 cm).
Source: D’Empaire, Prof. Gabriel Universidad de Venezuela.
6. Lebanon
An average penis size during erection: 6.6 inches (16.82 cm).
Source: Rafik Hariri University Hospital Researchm, 2007.
7. Belgium
An average penis size during erection: 6.4 inches (16.25 cm).
Source: Paedagogium Castri (Leuve) Belgium, 2007.
8. France
An average penis size during erection: 6.3 inches (16.01 cm).
Source: Recherche en Anthropologie; Universite de Orleans, 2006.
9. Czech Republic
An average penis size during erection: 6.3 inches (15.89 cm).
Source: Internationalizaci Univerzity v Praze, 2001.
10. Italy
An average penis size during erection: 6.2 inches (15.74 cm).
Source: Unibo, Dr. A. Piemonte Bologna.
11. Brazil
An average penis size during erection: 6.2 inches (15.70 cm).
Source: Dr. Paolo Palma, Claudio Carimba, Urologos, Brasilia.
12. Egypt
An average penis size during erection: 6.2 inches (15.69 cm).
Source: the faculty of Medicine of Ain Shams University, Egypt, 2004.
13. Mexico
An average penis size during erection: 6.2 inches (15.68 cm).
Source: Instituto Mexicano de Sexologia. A.C., 2003.
14. South Africa
An average penis size during erection: 6.0 inches (15.29 cm).
Source: The South African Department of Health (Facts and Statistics).
15. Denmark
An average penis size during erection: 6.0 inches (15.29 cm).
Source: Sexological Clinic, Neuroscience Centre, Copenhagen, 2005.
15. Morocco
An average penis size during erection: 5.9 inches (15.03 cm).
16. The Netherlands
An average penis size during erection: 5.9 inches (14.89 cm).
Source: Onderzoekscentrum i.o.v. NIBI Nederland, Utrecht.
17. Sweden
An average penis size during erection: 5.8 inches (14.80 cm).
Source: Statistika Centralbyran, Sweden.
18. Greece
An average penis size during erection: 5.8 inches (14.73 cm).
Source: University of Crete, 2005.
19. Scotland
An average penis size during erection: 5.8 inches (14.73 cm).
Source: Bioinformatics Research Centre, University of Glasgow, 2008.
20. Chile
An average penis size during erection: 5.7 inches (14.59 cm).
Source: Universidad de Chile, Dpt. de Urologia.
21. Ethiopia
An average penile erection: 5.7 inches (14.53 cm).
Source: Ethiopian Military database.
22. Israel
An average penile erection: 5.7 inches (14.50 cm).
Source: Kent Sepkowitz Research, 2005.
23. Germany
An average penile erection: 5.7 inches (14.48 cm).
Source: Dr. Ulrich Wetterauer, University Medical Center Freiburg, 2004.
24. Norway
An average penile erection: 5.6 inches (14.34 cm).
Source: Norwegian Social Science Data Service (NSD).
25. Turkey
An average penile erection: 5.5 inches (14.11 cm).
Source: Universite Hakkinda, Ankara 1998.
26. The United of Kingdom
An average penile erection: 5.5 inches (13.97 cm).
Source: Lidell Hart Centre London, 1996.
27. Canada
An average penile erection: 5.5 inches (13.92 cm).
Source: Organisme Statisque National Du Canada.
28. Spain
An average penile erection: 5.5 inches (13.85 cm).
Source: Dr. Pilar Cristobal: Universida de Navarra, 2003.
29. Suriname
An average penile erection: 5.2 inches (13.34 cm).
Source: The PAHO/WHO Representative Paramaribo.
30. Australia
An average penile erection: 5.2 inches (13.32 cm).
Source: Australia’s national agency for health and welfare statistics and information.
31. Japan
An average penile erection: 5.2 inches (13.28 cm).
Source: Japanese Journal of Sexology.
30. Russia
An average penile erection: 5.2 inches (13.21 cm).
Source: Clinical and Scientific Research Center of Russian Military BMenA.
31. The United States
An average penile erection: 5.1 inches (12.90 cm).
Source: Dr. Wessels H, McIlney Institue California, 1998.
32. Ireland
An average penile erection: 5.0 inches (12.78 cm).
Source: NUI Galway/NUIG/UCG Ireland, 1999.
33. Indonesia
An average penile erection: 4.6 inches (11.67 cm).
Source: Universitas Indonesia, Laporan Hasil Penelitian.
34. China
An average penile erection: 4.3 inches (10.89 cm).
Source: Kensley Report 1953, Shanghai.
35. India
An average penile erection: 4.0 inches (10.25 cm).
Source: Indian Council of Medical Research.
36. South Korea
An average penile erection: 3.7 inches (9.4 cm).
Source: Survey of Self-Reported Premature Ejaculation Prevalence and Characteristics in Korean Young Males by Hwancheol Son, Sang Hoon Song, Soo Woong Kim, and Jae-Seung Paick, 2010.
Regardless of available data in several journals, particularly in the United States, the data of penis size during erection based on Kinsley research much larger than above data (for the U.S) because they divide it to several ethnic groups such Caucasian, African-American, as well as other ethnic groups. While the journal data using a dominant local ethnic groups from the country.
