Stitch Fix Inc. said it would cut about 330 jobs as the personal shopping and styling service grapples with a slowdown in sales and widening losses.

The moves would affect roughly 15% of the salaried positions at the San Francisco-based company, and about 4% of its overall workforce, Chief Executive Officer Elizabeth Spaulding said in a memo to staff Thursday. Most of the reductions are in the company’s nontechnology corporate roles and styling leadership roles, the memo said.

The company on Thursday began notifying staff affected by the cutbacks. The job cuts are expected to result in between $40 million and $60 million of savings in the next fiscal year, which begins in August, the company said.

“We are in the midst of a transformation and we know not every day or every moment will be easy,” Ms. Spaulding wrote. “There will be tough choices along the way, and this is one of those.”

CNBC earlier reported on the layoffs. Stitch Fix said in a securities filing Thursday that it would evaluate other operating costs, including its real estate footprint.

The job cuts come as the company reported revenue in the April-ended quarter fell 8% from a year earlier and its losses more than quadrupled.

Shares in the company fell more than 10% in Thursday trading and dropped an additional 16% after hours. Shares closed the day down 93% from their peak in January 2021.

Stitch Fix is the latest e-commerce company to grapple with changes in consumer habits as a result of everything from persistent inflation to shifts toward spending on services instead of goods. Companies from Wayfair Inc. to Shopify Inc. reported record profits earlier in the Covid-19 pandemic as shoppers with fewer options stepped up purchases online. Executives from those companies, however, have said the retreat they have faced in recent months has been steeper than expected.

Stitch Fix’s struggles also illustrate the challenges facing personal styling services. Department-store chain Nordstrom Inc.

said last month that it would shut down Trunk Club, a clothing-box subscription startup it bought in 2014, after difficulties with growing the business profitably.

Stitch Fix, founded in 2011 with an initial focus on women’s apparel, provides personalized shipments of apparel, shoes and accessories. It has worked to grow its client base over the years and the range of products it could offer consumers. Last year it launched Freestyle, which lets consumers buy items directly from the company.

The company reported just over 3.9 million active clients in the most recent period, down 5% from a year earlier.

In the latest period, revenue for Stitch Fix stood at $492 million, and the company reported having problems in acquiring new clients in recent months. Its net loss was $78 million, up from roughly $18 million a year earlier.

Stitch Fix pledged to continue broadening its product offering and invest in technology and product, Ms. Spaulding wrote in the memo. It hired a new marketing chief recently, and Ms. Spaulding told analysts on a conference call that the company was moving into more digital channels such as TikTok and YouTube and increasing its use of influencers to help market its offerings.

Ms. Spaulding said the road ahead is challenging. The company expects revenue in the current quarter to decline between 13% and 15% from the prior year.

Write to Bowdeya Tweh at Bowdeya.Tweh@wsj.com