But, as the age-old question goes, does size really matter?
According to a 2012 study in The Journal of Sexual Medicine, the answer is yes - well, for some women that is. In particular, women who have frequent vaginal orgasms are more likely than other women to say they climax more easily with men with larger penises, according to the study.
"Male anxiety about penis size may not reflect internalized, culturally arbitrary masculine stereotypes but an accurate appreciation that size matters to many women," study researcher Stuart Brody, a psychologist at the University of the West of Scotland, told Live Science in 2012.
But men need not fret if they aren't well endowed. There's also a great deal of variability in women's size preferences, Barry Komisaruk, who researches female sexual response at Rutgers University, told Live Science at the time.
Another study, from 2013, found that penis size is a bigger factor for taller men. In the study, the researchers found that a larger penis had a greater effect on how attractive taller men were to women.