A study conducted by British online medical website Dr. Ed asked women and men from Europe and North America about their sexual health and happiness. Respondents had to guess the length of the average erect penis and also answer what an ideal penis is, length-wise.
No matter what people thought the average penis length was, everyone’s ideal length was always bigger. Some things really are universal.
Of the 2,121 respondents, between the ages of 18 and 75, 1,148 identified as male and 973 identified as female. Almost half of the survey pool was from the United States (1,055) while the rest lived in nine different countries throughout Europe.

The survey was presumably measuring heterosexual preferences because the conclusion reveals how important penis size is to women, but not how important penis size is to men. (It did, however, ask men how size affected their confidence.)
The research revealed that men believe both the average and ideal penis sizes are larger than what women thought.

On average, women perceived the average male penis length to be 13.8 cm and the ideal penis size to be 15.8 cm. Men, on the other hand, thought the average penis length on average is 14.1 cm and the ideal length is 16.6 cm.
When comparing what people believe to be the ideal vs. average penis sizes by country, Poland had one of the the highest bids. On average, the Polish respondents assumed the average penis size is 15.7 cm and the ideal penis size is 17.3 cm.
The U.S. fell somewhere in the middle with American respondents reporting the perceived average penis size as 14.3 cm and the ideal length as 17 cm.

According to the data, only 10 percent of men are dissatisfied with their penis sizes, while 45 percent are perfectly content. The majority of women (67.4 percent) reported that penis size is “somewhat important” while 21.4 percent said it’s “not important” and only 11.2 percent said it’s “very important.”

source: huffingtonpost.com