Nickelson Wooster, a fashion consultant and a frequent subject of street style photographers, is known, among other things, for his taste in shorts. He wears them long and short, loose and tight, in leather, wool and twill.

“Shorts are like skirts, and I think any woman will tell you there is no one length or shape that fits every single person,” said Mr. Wooster, 63, who goes by Nick.

On the surface, it might seem like shorts suffer from a case of nominative determinism — their name tries to tell us what to expect from their appearance. In practice, the length of shorts can vary wildly. They can reach down to the top of the shins or stop a few inches from the hip.

Ross Figlerski, 32, recently started leaning into truncated inseams. “I’m a bigger guy, and I find them a lot more flattering and reliable for whatever outfit I end up wearing,” said Mr. Figlerski, who lives in Brooklyn.

His fiancée also influenced his thinking about shorts. “She demanded to see more thigh,” he said.

Inseam trends move up and down like an accordion. In the 1950s, flared, foot-long Bermuda shorts washed up on American shores. Shorts shrunk from there until they crested with Dolfin shorts, the ubiquitous and tiny cotton athletic shorts worn by Richard Simmons and Arnold Schwarzenegger in the 1980s. Inseams had nowhere to go but down.

The 1990s and 2000s were dominated by denim, cargo and basketball shorts, all worn long and baggy. Look no further than ’N Sync, the basketball player Allen Iverson or the outfits in movies like “Clueless” and “Can’t Hardly Wait.”

The recent short-shorts trend seemed to start around the time that the hashtag #5inchseam began circulating on TikTok in 2020. Suddenly, the social media platform was filled with people clamoring for more men to show a little leg. (“5 inch shorts are the male version of cleavage,” reads the caption on a video with more than 30,000 likes.)

Since then, so-called thirst trap shorts have become a more broadly popular summertime staple for men, with some of the more adventurous adopting side-split running shorts that leave little to the imagination.

The designer Willie Norris said she was interested in “why the short inseam vigor is so strong with straight men.” Gay men, Mx. Norris added, have long chosen their inseam lengths without the same sort of heated debate: “This type of granular sartorial stance is something I see straight men participating in far more than gay men.”

“These shorter inseams have sort of seeped into the mainstream in the last few years,” said James Harris of the men’s wear podcast “Throwing Fits,” where he and his co-host, Lawrence Schlossman, regularly lampoon the discourse over what constitutes a fashionable inseam.

Mr. Harris suggested that five-inch inseams had become more widespread partly as a result of young women swooning over them on social media. For his part, he prefers either three-inch or nine-inch inseams.

“The longer inseams feel kind of familiar to me growing up in the 90s and 2000s,” Mr. Harris said. “It goes along with the baggier silhouette we’re seeing in men’s wear generally.”

Nostalgia isn’t the only thing driving inseam choices. Liam Burack, a 15-year-old high school sophomore from Johnstown, Colo., says that “quite short” shorts have been popular among his friends since the pandemic, largely for practical reasons.

“Shorter shorts to me are more comfortable,” he said. “Longer ones are just too heavy and too baggy.”

There are signs that shorts’ hems are slowly getting pulled back to earth, though. New collections from Louis Vuitton and Lemaire shown at the men’s wear shows in Paris last month featured inseams drooping past the kneecap.

Mel Ottenberg, a stylist and the editor in chief of Interview magazine, said he thinks “short shorts on the masses are great,” but that he was glad to see “longer, conservative and boring shorts again.”

“Apparently my taste in dad shorts is very on trend,” he added.

Mr. Wooster attributed the appearance of longer shorts at recent runway shows to high-fashion brands’ tendency to go against the grain once a trend goes mass market. “The minute the pendulum swings one way, I feel like the natural reaction is for things in those rarefied airs to change,” he said. “The true tastemakers end up going the opposite way just because.”

Some designers aren’t thinking too much about which way the wind is blowing. Daiki Suzuki, founder of the brand Engineered Garments, was a bit surprised to learn about the shifting style in short lengths. Mr. Suzuki, whose label specializes in adventurous and coveted interpretations of Ivy style and American work wear, said that he typically keeps inseams between nine and 11 inches when he’s designing a new pair.

“I view shorts as a distinct item,” he said. “Just as women choose between pants and skirts, I approach shorts as a separate category. While length is crucial, so is the width of the leg opening and the thickness of the shorts. I don’t think about trends that much.”

But even as some trends seem to dominate, there seems to be variety among every possible social group.

Zach Pollakoff, 39, remembered when, as a college student, it seemed like a “big statement” if someone was wearing super short shorts. “It was like, OK, he’s not a frat dude, he’s not an academic. That’s an indie music kid.”

But in recent years, he said, it has become harder to use clothing as a shortcut to grasp someone’s taste in music, for example. It’s not necessarily a bad thing.

“The rules about things like inseams have become a moving target,” Mr. Pollakoff said. “And it makes it sort of irrelevant to have a rule in the first place.”

Mr. Harris, the “Throwing Fits” co-host, said that was indicative of the general direction of men’s wear these days. “Everyone is doing everything,” he said.

As people seek style inspiration from an array of newsletters, social media influencers, glossy magazines and other cultural authorities, there is no universal idea about what is right or wrong to wear.

“There’s not one dominant market; there’s not one dominant archetype,” Mr. Harris said.

But for the guys who may still be debating how much leg to show this summer, Mr. Wooster had a piece of fashion advice.

“I’m wearing a length that is right at the knee,” he said. “Not below or above — right at the knee. I feel like that’s foolproof. It’ll never be bad. That’s the Teflon length.”