Does penis size matter?

How the survey measured

With a rigid ruler and a full erection, the survey instructed respondents to lay the ruler along the top side—the side facing upward when standing. The end of the ruler was pressed firmly against the body at the pubic bone so that body fat did not change the reading.

Respondents were told to hold the penis against the ruler, straighten any curvature without stretching, keep it pointed straight out from the body, and look directly down to read the measurement at the tip. Using one method made the self-reported answers somewhat more comparable.

Reported erect length

The approximate average based on the ranges was 6.13 inches, or 6.20 inches among respondents age 16 and older.

The most common single range was 6.0–6.4 inches, followed by 5.5–5.9 and 6.5–6.9. More than three quarters of the respondents placed themselves between 5 and 7 inches.

• Under 4 inches: 1.1%
• 4 to under 5 inches: 7.3%
• 5.0–5.4 inches: 11.5%
• 5.5–5.9 inches: 21.9%
• 6.0–6.4 inches: 25.6%
• 6.5–6.9 inches: 16.8%
• 7.0–7.4 inches: 9.3%
• 7.5–7.9 inches: 3.9%
• 8.0–8.4 inches: 1.4%
• 8.5–8.9 inches: 0.6%
• 9 inches or more: 0.4%

Underwear and reported length

The survey found an association between underwear choice and reported length, but it could not establish cause and effect—or rule out the possibility that neither caused the other.

That invites the obvious question: did tight underwear change size, or did size change underwear choice? The data cannot answer it. Self-selection, age, body type, reporting habits, and simple preference could explain the difference.

• Briefs wearers: 6.00 inches
• Boxers wearers: 6.25 inches
• Boxer-briefs wearers: 6.29 inches
• No underwear: 6.33 inches

Self-image and erection change

The self-arousal answers suggest that body confidence and reported size moved together in this audience. They do not show which caused the other, and either answer could have been influenced by the same confidence or reporting bias.

The grower-versus-shower answers also show why flaccid appearance is a poor predictor of erect size. The largest group reported a substantial change, while a small minority changed mainly in firmness.

• Respondents who said they became very aroused by their own image averaged 6.38 inches; those who did not find themselves arousing averaged 5.98 inches.
• 61.5% said they grew a lot from flaccid to erect; that group averaged 5.96 inches erect.
• 36.5% said they grew significantly but retained some flaccid length; that group averaged 6.41 inches.
• 2.1% said they changed little in length and mostly became stiffer; that group averaged 6.25 inches.

What respondents liked most

Length attracted the most attention in questions about dissatisfaction, but it was not what most respondents liked best. Shape, thickness, and simple tactile familiarity together outranked length by a wide margin.

• The way it feels in the hand: 46.2%
• Shape: 20.7%
• Thickness: 19.0%
• Length: 11.9%—average reported length 6.87 inches
• Hairiness: 2.2%

What respondents would change

Respondents who chose length as the feature they would change reported an average of 5.76 inches, more than an inch below the average among those who named length as their favorite feature.

• Length: 49.9%—average reported length 5.76 inches
• Hairiness: 17.3%
• Thickness: 13.5%
• Left or right curvature: 11.5%
• Up or down curvature: 7.8%

Reported averages by background

Within this self-selected reader sample, reported averages varied by ethnicity: African/Black 6.74 inches, Native American 6.49, Middle Eastern 6.28, European/White 6.26, Hispanic 6.03, and Asian/Pacific Islander 5.50. Those figures describe the survey respondents and should not be treated as population estimates.

Reported averages by hair color were black 5.92 inches, dark brown 6.15, light brown or dirty blond 6.20, blond 6.24, and red 6.09. The overlap among individuals is far larger than these differences between group averages.

These are correlations, not rules. Every category contained respondents reporting both small and large measurements, so neither ancestry nor hair color can determine an individual result.

Shoe size in the U.S. respondents

Average shoe size was 10.8. The sample showed a correlation between shoe size and reported length, but a reader survey cannot tell an individual’s size from his shoes.

Only U.S. respondents were used for this comparison because shoe-size systems differ by country. The smallest bracket contained 56 respondents and the size-14-and-over bracket contained 123, making the extremes especially sensitive to who chose to answer.

• Shoe size 7.5 and under: 5.85 inches
• Shoe size 9 and under: 5.96 inches
• Shoe size 9.5–12: 6.19 inches
• Shoe size 12.5 and over: 6.42 inches
• Shoe size 14 and over: 6.62 inches

What readers expected from enlargement pills

More than nine in ten expected no result, and respondents claiming a significant result were a tiny fraction of the sample. The survey did not verify the products, doses, measurements, or claims.

• Probably nothing: 91.8%
• Probably significant enlargement: 7.0%
• Tried them with no effect: 0.7%
• Tried them and reported significant enlargement: 0.4%

What 556 women said mattered

A later study using 3D models likewise found average preferences slightly above the measured population average, with the preferred size changing somewhat between long-term and one-time partner contexts.

Combining “very important” and “somewhat important,” 75% of the 556 women said length mattered at least somewhat and the same 75% said girth mattered at least somewhat. One quarter placed each trait in the unimportant category.

• 18% said length was very important; 22% said girth was very important.
• 57% said length was somewhat important; 53% said girth was somewhat important.
• 25% said length was unimportant; 25% said girth was unimportant.