Retail workers are doing the hustle just to pay the utility bills.

A record number of US retail employees are hustling for more part-time hours and side jobs to make ends meet.

Downsizing and waves of store closures — nearly 9,300 last year and about 2,500 already announced in 2018 — are trimming the ranks of full-time store employees. About 33,000 workers, for example, were axed when bankrupt retailer Toys ‘R’ Us shuttered its 735 US stores in March. Troubled retailer Sears continues to shrink and fire employees.

“It’s putting more pressure on existing full-time workers at our store to work twice as hard,” said Artavia Milliam, a full-time salesperson and 10-year vet at H&M on 18th Street and Fifth Avenue, told The Post.

“And it’s a lot more stressful to work here these days than it was a few years ago,” added Milliam, who earns a little over $15 an hour.

Despite the pressures, Milliam, 34, may even count herself fortunate. The company recently eliminated several full-timers at her location, as it ramps up the ranks of part-timers and locks horns with H&M union reps over demands for better conditions.

In a statement, H&M told The Post that it has informed union reps it would consider including a minimum guarantee of hours in a contract for part-time workers at its Manhattan stores, but noted that no agreement had yet been reached since issues still needed to be resolved.

Milliam isn’t doing cartwheels. The Brooklyn resident, who graduated from community college with an associate’s degree in computer technology, lives at home with her mother. Milliam’s personal budget is so stretched with living expenses that she’s looking to take a second job to make ends meet, she said.

She’s not alone. The ranks of retail workers include many who have two or more jobs. And they form part of the bottom 60 percent of US wage earners whom Oxford Economics recently identified as having to live paycheck to paycheck.

These workers are part of another group of Americans — nearly 4 in 10 — who have a “side hustle,” or second source of income, ranging from home repairs to child care, according to a Bankrate.com study.

More than half of that total are millennials, a demographic that includes many of today’s US retail workers.

Most employees at some of the biggest US retailers are now part-time workers. Scant or no benefits, and fewer hours, are being tacked onto often erratic schedules. Many are working multiple part-time jobs just to shore up personal finances.

A recent study by a labor rights group Organization United for Respect claims that about half of Walmart’s 1.5 million US workforce are part-timers, compared with 20 percent in 2005.

One part-time retail worker told The Post she’s nearing bankruptcy despite recently picking up an additional job as a consultant. “I still don’t make enough,” she said.

The stress on Milliam is evident as she sees a parade of workers unsure of how their next shift will shape up: whether it means 8 or 18 work hours in the week, or whether a worker will be asked to stay late for the night closing and come right back exhausted in the early morning for the opening.

That’s a practice known as “clopenings” the union wants banned. “It’s really a bad situation right now,” she said.