This is what the perfect male and female buttocks look like, according to science – and it’s all about the waist-to-hip ratio

Plastic surgeons have revealed the type of rear-end Americans find most attractive.

The findings, from two studies published in an academic journal, show that, size is not the most important factor when it comes to an aesthetically pleasing derriere on women, despite the ‘Kardashian effect’ on beauty standards.

In one study, by surgeons at Loma Linda University in California, experts recruited 1,100 men and women and asked them to look at pictures of eight different sets of female buttocks, which the doctors had digitally generated.

They were then asked to indicate to researchers which one they found the most attractive. Results showed that people found ‘waist to hip’ ratio of 0.65 most attractive. This number resulted in a more narrow waist that flared slightly into the hips.

For one of the studies, 1,100 men and women were shown eight digitally-altered images of women’s behinds and asked to say which they preferred. Every posterior got at least one vote, but results showed that a waist-to-hip ratio of 0.65 in women was most often ranked as attractive by participants. This ratio indicates that the buttocks is about 35 percent larger than the waist. A ratio of 0.60 (center) and 0.675 (left) were ranked as the second and third most appealing

The above three buttocks were ranked as the middle-three most appealing by participants. All buttocks received at least one vote

The above two digitally-altered images of female buttocks were ranked as the seventh and eighth most appealing by participants. The ‘Kim Kardashian derriere’ came in last place. Study participants were about half men, half women and mostly lived in the United States

Kim Kardashian, pictured in 2017 and 2022, is arguably best known for her perfect hourglass curves. But the beauty has had a transformation over the years and recently started displaying a more svelte figure

But the ideal buttocks is far from the extreme proportions seen on many A-list celebrity women famous for their hourglass figures.

In a separate study involving 2,000 men and women, participants were shown five images of male buttocks and asked to rate each from one to five — with those rated five being the most attractive.

The male buttocks ranked number one was also moderately sized, but the outlines of the muscle more defined.

Commenting on the female results, Dr Marc Everett, a plastic surgeon in New York City, told DailyMail.com: ‘The mid-2010s brought an explosion in popularity of  “Brazilian Butt Lift” or BBL [a procedure in which a doctor transfers fat from the belly, hips or thighs to the buttocks].

‘But these days we are seeing fewer patients requesting extreme results.

‘Instead, they’re going for more modest size fat transfers, which put them into the “unsuspecting” or “it could still be natural” category.’

Dr Everett adds he’s seen a recent increase in patients who want to reverse their rear-enhancing procedure.

‘I am seeing patients with some remorse about their exaggerated results,’ he says.

‘They are seeking remedies for oversized buttocks that are less fashionable this decade, or for buttocks starting to sag due to aging.’

The interest in BBLs was driven by large-reared celebrities including Khloe Kardashian, Cardi B and K.Michelle.

But with a shift in fashion many seem to have had the surgery reversed, with Khloe Kardashian appearing in 2022 with a slimmed-down figure.

The procedures have surged in popularity, with the number of BBLs rising from nearly 4,000 in 2011 to 61,000 in 2021.

In the first study, scientists began digitally altering a stock image of a pair of female buttocks to create eight images with varying waist-to-hip ratios.

This is the main determinant of butt size — along with the amount of body fat inside the buttocks — and made the computer-generated images appear to have varying volume in buttock tissue.

The larger a person’s waist-to-hip ratio, the more fat they had around their waist, making their behind appear less curvy, scientists said.

And the smaller the waist-to-hip ratio the less fat they had around their waist, making their buttocks appear curvier.

The images were then shown to 1,000 study participants recruited via social media.

Almost all participants were from the US — half male, half female, and the majority were aged 25 to 34 years old.

Researchers found the buttocks with a waist-to-hip ratio of 0.65 was most popular. Forty-four percent of respondents said this was their preferred option.

A ratio of 0.65 means that the buttocks is about 35 percent larger than the waist. It was measured by wrapping a tape measure around the waist at its smallest point and the hips at their largest point.

In second place was the slightly smaller ratio of 0.60: a quarter of the sample favored this size.

One in 10 participants liked the second largest butt the best — 0.675. And the butt considered least attractive had the lowest waist-to-hip ratio of 0.55.

There is variation in waist-to-hip ratios across the population, doctors said, but anything at 0.6 or below would be ‘hard to play off’ as natural.

In the second study, researchers asked 2,000 men and women to rank five digitally-altered images of male buttocks from one to five by which they found most attractive. The scores were then averaged to reveal the most popular buttocks, which indicated one with a gluteal trochanteric index (GTI) of 0.66 was most appealing (left). A GTI of 0.64 (center) and 0.68 (right) were ranked as the second and third most appealing

The buttocks with a ratio of 0.62 (above left) was voted the fourth most attractive while the other, with more accentuated curves and a ratio of 0.58, was voted the least attractive for men

Khloe Kardashian, pictured in 2014 and again in 2022, is believed to have had surgery to augment the size of her butt. She is shown with a much larger one initially before showing off her more slimmed down appearance

Cardi B revealed in 2022 that she had had butt fillers taken out of her behind. She is shown, left, in July, and, right, later in the year after telling fans she had had them removed

In the study on male butts, researchers asked 2,000 people to rate five digital images of a male buttocks from three angles: Behind, at a curve and side on.

The participants ranked the images from 1 to 5 with 5 being the most attractive and their scores were then combined to get an overall figure.

Participants were recruited online and 61 percent were male aged between 25 and 34 years old.

They were all in the United States and half of the participants were from a white background while 75 percent were heterosexual.

Results showed that, overall, participants preferred a buttocks that was ‘moderately enhanced’ and ‘well-proportioned’ in appearance.

Dr Ashit Patel, a plastic surgeon in North Carolina who led the study, said: ‘In our survey, raters thought the ideal male buttocks shouldn’t be too wide and should retain the characteristic dimple on the sides.’

Results showed that from behind, a gluteal trochanteric index (GTI) of 0.66 was most popular — with an average score of 3.1.

The GTI was measured by dividing the distance from the thinnest point of the waist to the bottom of the buttocks by the widest point of the buttocks. Researchers said they used this on men instead of the waist-to-hip ratio because of differences in fat distribution between the two genders.

A ratio of 0.66 means the buttocks is about 34 percent larger than the distance from the waist to the bottom of the behind.

It was followed by a ratio of 0.64 with an average score of three and 0.68 with an average score of 2.9. At the other end of the scale, participants were least likely to rate 0.58 as their favorite.

For the other views, however, participants ranked the buttocks with a GTI of 0.64 as the most appealing.

Among gay participants, results showed participants were most likely to rank the ratio of 0.62 as the most appealing.

Researchers said there was a significant difference in responses by region, with those who lived in southern areas of the US most likely to say they preferred a more voluptuous buttocks on men.

Dr Patel said: ‘Our study is one of the first to really focus on what makes the male buttocks most attractive.

‘We believe the findings will be helpful in discussions with patients considering gluteal enhancement and provide guidance in achieving optimal results and patient satisfaction.’

Interest in male buttocks enhancements has been rising in recent years — with the numbers coming forward rising with the proportion of all butt alteration surgeries done on men rising from 2.2 percent in 1997 compared to 6.2 percent in 2012.

This study, also published in the journal of Plastic and Reconstructive Surgery this year, aims to give people a baseline on which butts are most appealing.