Penis size matters, but how does it matter? What sizes do people prefer, how much importance does it have, and how much do preferences vary across individuals?
Heterosexual Women's Penis Size Preferences
『Do all women prefer big dicks?』
No. Many women have no appreciable size preference, and the preferred sizes among women that do have notable size preferences are quite variable. there are some who prefer short, thin, average, long, thick, and any combination of lengths and girths therein. However, the average of these preferences is a little bit above the average male erect length and girth.
『So someone with a penis size that isn't at the most preferred region is at an overall disadvantage to someone who is?』
Sure, but the degree of disadvantage is usually so little that it would hardly matter for the vast majority of men.
In studies that specifically ask women to rate how male attractiveness is affected by different flaccid lengths, while they demonstrate an overall visual preference for above average lengths, the effects are usually less than those of other body-type attributes (these studies also suggest significant variation between different geographic populations of women, probably due to differences in cultural perceptions of penis size). In the following study data, the flaccid lengths relative to the model height would have the shortest at about 3 inches and longest at about 5.7 inches if one assumes the model has the average male height of about 5'9 - 5'10". Personally, I find such flaccid size data a bit incomplete since I'd expect women to associate larger displayed flaccid sizes with increased male arousal during partial erection, which could bias the results in favor of larger than typical flaccid sizes being more attractive in such simple visual comparisons.
Data Sources: Dixson et al. 2006, 2006, & 2009
Data Source: Prause et al. 2015 Supplemental Data
Popular western culture, media, and porn industries have been pushing the "bigger is better" notion for so long that big dicks have become normalized almost to the complete exclusion of anything else. To the point that I'd be surprised if it didn't cause many women to internalize that they should prefer larger than they actually prefer. But nonetheless, when you actually assess women's preferences it's clear that the popular notion is untrue, because the average of all their different preferences is consistently shown to be only a bit above the average penis size.
Johnston et al. 2014: Ask women what size they prefer.
Average Ideal Erect Length: 6.09" (0.79" above what they reported for the male average)
『Women self-reporting sizes? We can't expect people to give reliable distance estimates.』
Alright, then let's remove that problem.
Prause et al. 2015 - 3D Model Study: Have women choose their single most ideal size from among 3D-printed penis models of many different sizes.
Data Source: Prause et al. 2015 Supplemental Data
『So most of these women are probably lying because they don't want to admit that they prefer guys with bigger dicks, right?』
Stewart et al. 2009: Measure male partners of pregnant women in Australia.
Average Bone Pressed Stretched Length: 5.91"
『Maybe those women are mostly settling but they'll probably still cheat for bigger dicks?』
Well according to 3 separate studies approximately 85% of women were satisfied with or did not wish to change their partner's penis size.[1],[2],[3] So while it's true that in around 15% of couples the woman would prefer her partner be larger or smaller, and though that is not a negligible minority, it's still rather uncommon, and that doesn't tell us how much those women care that their partner's penis isn't their ideal. As shown above in the first Prause graphic, only about a quarter of women claim to have ever had penis size be a factor in ending a relationship with a partner, which based on the average of 6 sexual partners these women report, there would be overall just under a 5% chance of penis size (too big or too small) being a factor in ending a relationship. This overall 1 in 20 chance will of course be much higher at the extremes of penis size and lower with more typical sizes. Nonetheless this suggests that while 15% of partners may have less than satisfactory sizes, it only contributes to ending a third as many relationships. Overall it's clear that women who settled for outside their ideal and then went so far as to cheat due to size incompatibility would be quite uncommon. But we can find better studies that completely remove the concern of women settling for different than their ideal.
Female Dildo Size Preferences - Informal Study: Randomly sample women on Reddit who mentioned their personal favorite dildos, then determine dimensions of each dildo from information available online.
Data Source: Female Dildo Size Preferences - Informal Study
When averaged, all these women's dildo preferences yield:
Insertable Length: 6.23"
Circumference: 4.80"
Additionally, a random sampling of comparable dildos showed that women on average are not choosing larger sizes than are available, and if anything may actually prefer slightly smaller lengths and girths than are typically available.
These dildo preference results agree with the previous studies and demonstrate the consistent conclusion that the average woman's preference is just a fraction of an inch above the average length and girth of a man's erect penis.
『But aren't those lengths Non Bone-Pressed and therefore far from the average male penis length?』
Not a single study mentioned on this page uses NBP lengths, so no. Excluding the lengths of the 3D-model study which were open to individual interpretation, all of these studies' lengths fall into the same category of insertable/functional/BP lengths. And the insertable dildo lengths themselves are already a maximal estimate since people may prefer to use less than the entire insertable length of the dildo.
A broad conclusion I can offer after doing all this research on the topic of women's sexual preferences is that: of all the mature women in the world, a very small portion of them aren't sexually inclined, of the remainder a very small portion feels almost no physical sexual pleasure and can barely if at all orgasm, of the remainder a sizable minority doesn't even enjoy penetration (and even among those that do the majority still find other forms of stimulation such as clitoral and vibrational more enjoyable than regular penetration), of the remainder that enjoys penetration (people who would be inclined to use dildos) the majority place more importance on other factors such as rigidity, shape, curvature, ridges, etc. than they do on size, however they do typically have a minimum usable length and a range of girths that they prefer for better stimulation, within this group there is only a very small minority that prefers the feeling of being stretched by large girths (6-9"+ avg. girths) or stretched by deep penetration (7.5"-8"+ lengths), instead the vast majority of women prefer sizes of avg. girths within 3.5-5.5" and even though insertable dildo length is likely to be an overestimate since women only really care that a dildo is long enough while additional length may go unused, they still usually only prefer total usable lengths less than 7" and instead prefer typical penetration stimulations such as from g-spot and/or thrusting stimulation from naturally occurring male penis sizes. Furthermore, the vast majority of these women prefer the intimacy of sex with a caring lover to any dildo.Now you might argue that surely the above statements and data can't be correct because seeing all those women in porn going crazy for big dicks is all the evidence needed to prove that a bigger dick is always better, right? But you see, porn is about as real as WWE wrestling on TV. Sure the stunts are usually real, but even the most genuine examples are still just exaggerated portrayals for entertainment purposes. So there's really no merit to using such fiction as a way to judge women's preferences, and if we're being completely honest the vast majority of women would be relieved if you didn't make the mistake of using porn as a reference for how to pleasure women, because most of what pornstars do to make it more visually arousing amounts to a reality of pretty mediocre sex for women.
As a final thought experiment for you to better understand women's penis size preferences, I'll point out that the size of the penis has almost no significance except by comparison to the size of what it is inserted into. For a couple having intercourse, the penis is only large or small in comparison to the size of the vagina. A male-female relationship where his penis is too small or too large, is just as much a relationship where her vagina is too big or too small. And just as penises come in a wide array of different sizes so too do vaginas vary in size.[1],[2],[3],[4],[5] As such you can think of women's penis size preferences as a mirror-image of men's vagina size preferences. When you consider how vagina size matters to guys you'll probably immediately understand that while on average, a guy would prefer his partner to have a smaller than average vagina, he also really doesn't care that much how tight or deep his partner's vagina is, as long as it isn't too extreme.
Additional Graphics:
Homosexual Men's Penis Size Preferences
There really isn't much data available to determine the penis size preferences of men who are attracted to other men, but the decades old Kinsey Study does have some data on the subject. Granted it uses nonspecific self-reported perceptions with respect to "small" "medium" and "large", so it should probably be interpreted with respect to what sizes they typically consider themselves to be, and we can use data from another study of non-heterosexual men for that. Similar to results from women, 40% of the homosexual men reported no notable penis size preference, with the remainder skewed in favor of larger sizes (much like men were skewed towards self-reporting themselves as above average).
Data Sources: Gebhard & Johnson - The Kinsey Data & Grov et al. 2010
Another more recent and more detailed self-reported study on the subject of preference for partner's penis size comes from Serbia.
Data Sources: Bjekic et al. 2018
According to the self-reported survey by Grov et al. 2010: Men who claimed to have below average penises were significantly more likely to identify as “bottoms” (anal receptive) and men who claimed to have above average penises were significantly more likely to identify as "tops" (anal insertive).
Data Source: Grov et al. 2010
Data Source: Moskowitz & Hart 2011
Data Source: Male Dildo Size Preferences - Informal Study
In comparison to the same dildo study on women, men preferred on average: 0.73" more length and 0.27" more girth than women. This suggests that anal receptive men tend to have slightly higher size preferences than women. Additionally, a random sampling of comparable dildos showed that men were favoring dildo retailers that typically had appreciably larger dildo sizes available compared to those retailers favored by women.
Data Sources: Male Dildo Size Preferences - Informal Study & Female Dildo Size Preferences - Informal Study
Men's Personal Penis Size Preferences
How do guys tend to feel about their own penis?
Let's be honest, chances are:
You along with the vast majority of guys don't actually want the ideal penis size which is most likely to be preferred by potential partners. Even if you did have that size you'd just think it's too small and you'd be insecure that it isn't bigger. Realistically if you were actually concerned about being better in bed, you'd be on some other site learning about how to be a better lover, instead you want to know how the size of your dick compares to other guys because you've internalized a fantasy which measures your value as a person based on the size of your dick.