< Ask the doc

Does size matter?


Does size matter?


The size of what? And to whom?

I’m going to assume this is a question about penises.

Penis size might matter to the person with the penis or the people they share it with.

There are two recent scientific publications that help to answer the question:

  1. The effect of penis size on partner sexual satisfaction: a literature review
  2. Average-Size Erect Penis: Fiction, Fact, and the Need for Counselling

Men’s penis sizes probably matter more to them than they do to their sexual partners. A study of more than 25,000 heterosexual men found that 45% wanted a larger penis. A similar study of around 1,000 men who have sex with men found that 34% wished their penis was bigger. Only 15% of a group of over 25,000 heterosexual women wished their partner had a larger penis. Other studies of heterosexual women suggest that penis length is not quite as important as girth (width). Unfortunately, there’s no scientific studies of men’s satisfaction with the size of their sexual partners’ penises.

Like for all body parts, there’s a lot of variation in penis size. A review of scientific data, from studies with a total of over 15,000 people, shows that 95% of men have an erect penis length somewhere between just under 10cm to about 16.3cm.

For some men, it doesn’t matter that their penis is a normal size — they feel like it’s too small and they become preoccupied or distressed by what they think is problem. Spending money on penis lengthening devices or opting for surgery is probably not going to help these men feel better about the size of their penis, and the most effective way to deal with this problem is to talk to a psychologist or sex therapist.

A/Prof Tim Moss
A/Prof Tim Moss

Associate Professor Tim Moss has PhD in physiology and more than 20 years’ experience as a biomedical research scientist. Tim stepped away from his successful academic career at the end of 2019, to apply his skills in turning complicated scientific and medical knowledge into information that all people can use to improve their health and wellbeing. Tim has written for crikey.com and Scientific American’s Observations blog, which is far more interesting than his authorship of over 150 academic publications. He has studied science communication at the Alan Alda Centre for Communicating Science in New York, and at the Department of Biological Engineering Communication Lab at MIT in Boston.

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