With weddings postponed and offices shut, business was bleak at Woodside Tailor Shop in Queens during the long months of pandemic lockdown. There was no need for party dress alterations, or any pressure for slacks to be hemmed.

But about three months in, things started picking back up in June, with one particular service in sudden demand: People needed a bit more breathing room in their clothing.

Everybody got fat! said Porfirio Arias, 66, a tailor at Woodside. Its not only in New York. Its all over the world that people got fat.

In a city where gyms are still closed, and Netflix and couch the safest evening entertainment, the phenomenon of stay-at-home weight gain playfully called the Quarantine 15 by some has brought an unexpected windfall for some tailors. Some say they have seen business rise by as much as 80 percent, with customers asking for buttons to be moved, waistbands lengthened and jackets made more roomy.

If some people are uncomfortable, they go work out and do whatever, said Michael Shimunoff at La Moda Custom Tailors in Queens. Some people just let out the pants.

The boost in business has been welcome for many tailors, who often operate in storefronts shared with dry cleaners, which have suffered mightily during the pandemic. Dry cleaning businesses at the peak of the pandemic lost an estimated 80 to 90 percent in sales compared to previous years, and are still down about 40 to 50 percent, according to data collected by the North East Fabricare Association.

Smaller tailors who specialize in alterations have suffered more than custom clothing makers, whose clients have postponed receiving wedding dresses and tuxedos, but generally have not canceled their orders, said Alan Rouleau, the president of the Custom Tailors and Designers Association.

You cant do tailoring without being in somebodys face, Mr. Rouleau said. We are in a high-touch business.

Many tailors fear that the industry may not bounce back even as more people return to work, if the traditional workplace culture shifts to the new work-from-home ethos meaning more sweatpants and fewer bespoke suits that need to be cleaned, pressed or altered.

Of course, not all New Yorkers have been able to work from home, and the ability to sequester has largely fallen along socioeconomic lines: Putting on pandemic pounds is a small downside of what is in essence a tremendous privilege.

In Woodside, Mr. Ariass entire extended family his wife, two sons, daughter, brother-in-law and mother-in-law all had their pants let out this month. Or rather, they loaded Mr. Arias with their clothes to take to his shop so he could make the required alterations.

He said New Yorkers should not feel bad about needing a few more inches of room. They cant go out, they dont have a room to make exercise, so they dont have a choice, he said.

Mr. Arias can speak to the challenges firsthand: He said he has had to take needle and thread to his own trousers. I got fat, too!

At T & J Crystal Cleaners in Long Island City, Queens, David Choi said he has been trying to dissuade customers who ask him to loosen their clothes because they gained weight during the lockdown. The process sometimes distorts the original fit of the clothing so it no longer drapes well, he said, and he fears that his clients will not be happy with the result.

Instead, he urges customers to wait it out, reminding them that pandemics and pounds too shall pass.

I dont say, Go try the gym, Mr. Choi said. I cant say that, but I am not happy to make my money with this kind of job. So he said he has tried flattery, telling his customers that the extra pounds added something else besides pure weight. Some ladies still look sexy! he said.

Nicolas Jacquet, a custom suit specialist at Brooklyn Tailors, which crafts bespoke men's wear, said he recently adjusted a few waistlines on the custom suits of grooms whose measurements were taken before the pandemic began. He recommends fabrics with stretch and give to deal with inertia-based weight gain, like wool or blends with elastane.

We will tailor the suits to make the customer feel good about himself, Mr. Jacquet said, adding that with his clients weddings postponed or dramatically contracted, few are focused on their weight. They have a lot more issues to think about, he said.

At Alteration Concept, a basement tailor shop in the West Village in Manhattan, a debate was taking place between Chung Moon, the owner, and a woman who wanted to have the waistline of her jeans expanded.

Mr. Moon gently suggested that the woman might not like the darts that he would have to add to her jeans.

Sourdough is making me feel good right now, she said. Im not going to stop eating bread I need to feel good right now. The customer, as usual, was right: Mr. Moon ended up expanding three pairs.

Elsewhere in his shop, five pairs of Theory slacks and a blazer were awaiting enlargement. Mr. Moon, 49, said he was dubious that lockdown weight gain is solely to blame.

The pants were tight before, but we were so busy, even if pants were a little tight or a little snug, we didnt really feel that, he said. Right now, you have a lot of time, and a lot of thinking going on.