Recently came across this article via Andrew Sullivan. They measured the stretched flaccid penile length, circumference at the base, and testicular volume with a Prader orchidometer for 6,200 subjects age 0-19.
The data for 19-year-olds was:
Length mean 9.46 cm (3.72 inches), SD 1.12, 5th percentile 8.00, 95 percentile 11.00.
Circumference mean 9.67 cm (3.84 inches), SD 0.91, 5th percentile 8.20, 95th percentile 11.35
Right testicular volume mean 16.56 mL, SD 4.39, 5th percentile 10.00, 95th percentile 25.00
Left testicular volume mean 15.99 mL, SD 4.52, 5th percentile 10.00, 95th percentile 25.00
Reference:
Growth and Development of Male External Genitalia
A Cross-sectional Study of 6200 Males Aged 0 to 19 Years
Analia Tomova, MD, PhD; Fnu Deepinder, MD; Ralitsa Robeva, MD; Hristina Lalabonova, MD, PhD; Philip Kumanov, MD, PhD; Ashok Agarwal, PhD, HCLD
Arch Pediatr Adolesc Med. 2010;164(12):1152-1157. doi:10.1001/archpediatrics.2010.223
The data for 19-year-olds was:
Length mean 9.46 cm (3.72 inches), SD 1.12, 5th percentile 8.00, 95 percentile 11.00.
Circumference mean 9.67 cm (3.84 inches), SD 0.91, 5th percentile 8.20, 95th percentile 11.35
Right testicular volume mean 16.56 mL, SD 4.39, 5th percentile 10.00, 95th percentile 25.00
Left testicular volume mean 15.99 mL, SD 4.52, 5th percentile 10.00, 95th percentile 25.00
Reference:
Growth and Development of Male External Genitalia
A Cross-sectional Study of 6200 Males Aged 0 to 19 Years
Analia Tomova, MD, PhD; Fnu Deepinder, MD; Ralitsa Robeva, MD; Hristina Lalabonova, MD, PhD; Philip Kumanov, MD, PhD; Ashok Agarwal, PhD, HCLD
Arch Pediatr Adolesc Med. 2010;164(12):1152-1157. doi:10.1001/archpediatrics.2010.223
