The Truth About “Girl Inches”: Why Women Overestimate Penis Size

For every man worried about not having a big enough penis, there's a woman who thinks it's much bigger than it actually is

May 28, 2021 9:09 am
Measuring tape, banana, hot dog and pickle
We're all hopelessly confused about penis size.
Gabe Serrano for InsideHook/Getty

Nick once hooked up with a petite girl in college who, lying next to him post-coitus, told him something he wasn’t expecting to hear. “You have a huge dick,” she said. “Like, that’s intimidating.”

“I was just kinda taken aback,” says Nick*, a St. Louis resident who’s 26 and works in sales. He’d lost his virginity at 16, and by that point in college had had sex with a handful of partners. But none of them had ever paid so much attention to his penis. 

After his next girlfriend offered similar observances, Nick, who’d believed his penis was average, thought he should measure it. He did, and after conducting some internet research, he learned that his seven and a half inches rank in the 99th percentile of men. He was “astonished,” and admits “I felt very special and I was definitely proud of it.”

Recently, Nick had sex with another woman who told him his dick was big. The déjà vu prompted him to ask her how big she thought it was in explicit terms. “She was like, ‘I don’t know, 10 inches?’” Nick recalls. He responded with a little laugh, and said, “No. Not at all.”

This latest scenario Nick recounts is a manifestation of what the internet calls “girl inches,” an issue of penis size misperception that is far more widespread among those who don’t have penises of their own than many size-conscious penis-havers might suspect. 

The Proof


Urban Dictionary defines “girl inches” as “when a girl thinks a guys dick is much bigger than it actually is.” “So when a girl sees a dick thats around 6 inches,” the website supplies as an example, “she’ll think its [sic] 8 or 9.” 

Reddit is also home to a hefty share of girl inches insight. 

“I was with one girl who was convinced she had never been with a guy less than 8 inches, which is statistically insanely unlikely,” wrote one male Redditor in a post about it. In another post on the topic, user arusach said that his penis is six and a half inches long with a five-and-a-half-inch girth — “not too big,” he disclosed, but “bigger than average.” Arusach wrote that he showed it to a woman who “thought it was like 8 or 8.5 inches,” and he then told her “it’s not that big,” but “she kept arguing.” He exclaimed in closing: “what’s with that?????”

One guy went so far as to generate a girl inches formula, because apparently the oft-utilized computation of “actual length” plus two “imaginary inches” is the wrong approach. Girl inches, he declared, “is way more complicated than that.”

For men who have penises smaller than five and a half inches, “your size in girl inches will be reduced by one inch,” observed the user 192cmcock. If a penis is longer than 5.5 inches, widely recognized as about average, “your size will be increased by exactly 1.5 imaginary inches.” Why? Because “we all know that the average penis in girls inches is 7 inches right?!” he wrote. (The universe should “trust” this formula, 192cmcock continued, because his seven and a half inches have twice been identified as a nine-incher, he wrote.)

For eight-inch dicks, just round up to 10 in girl inches, 192cmcock deduced, and beginning at eight and a half inches, girls consistently overestimate by three or four inches. “At 9 inches and above, believe me there’s no formula anymore,” he wrote in conclusion, “just say that you have a 16-inch dick and you will easily get away with it.”

In the comments, user Separate Tea, who identified herself as a woman, said this formula checks out in her personal experience. “I didn’t realize how big 7.5 inches actually was until my ex literally measured it before my eyes and I realized how inaccurate my estimates had been,” she wrote. “I thought he was 9 inches … exactly what the post formula predicts LOL that’s why I was dying when I saw this.”

The Reasons


Why is there such rampant misunderstanding of penis sizes running through the female community? Is it because, as one Redditor guessed, they’re “biologically wired to be attracted to penises and therefore see them as bigger than they are”? Perhaps, when giving blowjobs, another Redditor posited, they get so up close and personal with penises that they seem much bigger?

No, despite the phenomenon’s gender-slanted label, “girl inches” exists mostly for the same reasons that men have the exact same handicap.

“Girl inches are actually ‘guy inches,’” says Magnus Cox, 35, a cognominal web developer in Ohio who authors The Big Dick Guide, a blog about, well, you can figure that out. Cox founded the blog because his extraordinarily large penis (8.5″ x 6″) generated unique life experiences, and he wanted to help inform other well-endowed men.

The two primary reasons behind girl inches, in Cox’s opinion: Men perpetually lying about their penis size and porn.

Whether it’s because they’re totally ignorant, ill-informed or, fueled by social pressures, want to impress their sexual partners, men often do not disclose truly representative size measurements of their penises. A 2019 medical journal study found that only 27 percent of participants said their member measured less than six inches, while 31 percent of the men rated themselves beyond seven inches. If both of these outcomes were accurate, they would push the average penis size well above the accepted five to five-and-a-half-inch median.

“Tens of thousands of penises have been measured and we know the average,” Cox says, adding that the number of measured manhoods, for science, may be even higher than that. Guys tend to throw out the seven- or eight-inch number, Cox continues, but, in front of women, “They’re not busting out a ruler [and] measuring it, because the last thing you want to tell them is ‘Nope, that’s five.’”

In his blog post about girl inches, a phenomenon he calls “hilarious,” Cox summarized all the ways in which porn uses camera and casting tricks, among other means of deception, to exaggerate the sizes of in-frame penises. “But the biggest thing that porn does is just outright lie about dick size,” Cox wrote. “Most porn actors are at least above average size, and some are truly large, but it’s not uncommon to see them adding three to five inches to their measurements. If porn tells you that the seven-inch dick you’re seeing is 10 inches, then when you’re presented with a penis in real life your perception of size is going to be terribly skewed.” 

Cox himself has experienced “girl inches”: a woman once insisted that his manhood was “at least a foot long.” In spite of measuring it in front of her, she still insisted it was 12 inches, not eight and a half — perhaps a testament to how influential cultural depictions of penises are to our psyches. 

A gender-neutral explanation for “girl inches,” Cox notes, is that “humans are terrible at estimating sizes of things that we don’t typically measure.” This evolution-induced impairment goes for not only object measurements, but guessing weights and distances as well.

The Toxicity 


If “girl inches” was spawned by tall tales authored by guys as well as cultural and evolutionary influences, then the term itself is a deflection of male responsibility for the issue, and inherently misogynistic. This is reflected in the language of many Reddit posts on the topic written by men. (To u/Tiny_Letterhead9020, who predicted with absolute certainty that my article would “just say we’re perpetuating toxic masculinity,” this section’s for you, pal.) 

Like in the posts included earlier, men appear to be quite angry about girl inches and express those feelings with barrages of adverbs, LOLs and punctuation marks. 

“So of course this sub really taught me about girl inches and how women typically know nothing about penis size,” wrote u/Optimum2526, in a recent post he titled “Girl Inches LOL.” He went on to recount that, after a female coworker of his said her partner’s penis was nine inches, he told her “she was more than likely wrong about the size of his tool.” The woman “had no idea” that the average penis size was around five inches and “didn’t believe google,” which told the scribe “all [he] needed to know.” 

The gender-linked term and posts like this have prompted other men to speak out against them. “Why should we trust a guy regarding women being wrong about size? Are men somehow automatically more trustworthy than women?” wrote u/VitaminZebra in one such post, while u/pippisthing told me in a Reddit comment, “I do not like the term ‘girl inches’. Girls do not have to do a lot with it.”

I also interviewed two women who both said they were fascinated by Reddit’s penis-size discourse. Each of them indicated that they in fact empathize with the men who get bent out of shape about girl inches.

“I get the sense that a lot of men have felt victimized for not having a large penis, and as a woman, I’ve felt victimized for the appearance of my genitals, so I know how horrible that feels,” said Carey* in a Reddit message. “I really can’t be mad at them for having those feelings.” 

She added that it’s important for men to “have a space where they can vent about their insecurities,” but does feel their anger in the case of girl inches is “a bit misdirected towards women.” 

“I think men should really dig deep and think about where these insecurities come from, aside from just some womens’ perceptions,” Carey wrote. 

“I think it’s misogynistic, but not misogynistic with the intent to harm women,” says another woman, who asked in a phone call to be referred to only by her first name, Catherine. She freely uses the term “girl inches,” in spite of its misogynistic roots and the irony behind it, because in her mind, mis-measuring is understood to be a gender-agnostic problem. 

Catherine also takes umbrage with what she feels is a real problem of judgment on the part of women. “It’s not proper to be talking about someone’s genitals in the first place,” she says, adding that women “do a lot of that.”

In his blog post, Cox blamed the culturally held belief that “bigger is better” on women also forging false stories about their sexual partners’ members. And in the aforementioned post about the misguided female coworker, the woman said to u/Optimum2526 that he only believed she was incorrect about her partner’s penis size because his “must be small.”

A Brighter Future


Both men and women would be better off if they were more informed about penis sizes. Women wouldn’t go around believing that a man needs to have 10 inches to satisfy them sexually, and men wouldn’t feel shitty about having penises that are big, average or even small

We’d also all be having better sex. With added confidence, men with more modest-sized penises can learn how to use them effectively, while dudes with big dicks can ease up a little. 

Nick, that guy with the “intimidating” penis from earlier, told me that, prior to measuring his penis and learning how relatively large it was, he probably was hurting women with it. “Almost every girl, when I would try and go in all the way, it would hit their cervix or they would push me back,” Nick says. “They wouldn’t say why and I just didn’t get it.”

On the other hand, women — whose varied vagina sizes may be a deciding factor in sexual pleasure — can also determine their penis-size preferences more astutely. They might be surprised to learn that they are decidedly not size queens.

In another Reddit post by a man, titled “Reverse girl inches,” user DannyTheBoyyy said he once asked a woman what her ideal dick size was. She said, “Enough to do damage.”

“Instinctively I roll my eyes expecting some insane number,” wrote TheBoyyy, Danny. 

He asked her, “And how big is that?” 

The woman replied: “14 centimeters.”

In inches, that’s five and a half. Right about average.


*Names have been changed for purposes of anonymity.

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