Determining the average penis size for a group of males is more complicated than you might imagine. Unfortunately most information about average penis size comes from popular culture and not science.
The results from three studies of penis size where the measurements were taken in a laboratory setting give the following ranges:
Average penis length (flaccid/not erect): from 3.4 inches to 3.7 inches (8.6 cm to 9.3 cm)
Average penis length (erect): from 5.1 inches to 5.7. Inches (12.9 cm to 14.5 cm)
Average penis girth (circumference when erect): from 3.5 inches to 3.9 inches (8.8 cm to 10 cm)
A penis that falls substantially below these values is referred to as a Micropenis or Inconspicuous Penis. Although this generally does not prevent a man from being sexually active this condition may have psychological effects especially when teased by peers.
