Aldi overtakes Asda to become third-largest in UK by grocery market share

The discounter captured 9.8% of the grocery market in the four weeks to May 18, edging ahead of Asda’s 9.4%, according to Kantar data seen by The Grocer. The shift represents a dramatic turnaround from the 12 weeks ending on the same date, when both chains were tied at 9.8%.

Aldi’s ascent has been driven by strong sales growth of 8.2% year on year over the period, while  Asda sa a 6.7% fall, highlighting the contrasting fortunes of the two retailers.

“In the latest data we have taken third spot,” Aldi UK and Ireland chief executive Giles Hurley told The Grocer. “That’s not an objective for us. We don’t benchmark on placement in the market. But it’s an interesting output of our growth, and it’s exciting.”

The milestone comes as seven in every 10 UK households shop at Aldi, underlining the discounter’s growing reach.

However, the picture varies depending on which metrics are examined. Under Kantar’s broader retail measurements, which include all store transactions except fuel and concessions, Asda maintains a lead with 12.1% market share compared to Aldi’s 11.1%. Yet even here, Aldi has gained ground from 10.8% a year ago, while Asda has fallen from 13%.

Asda disputed the significance of the grocery-focused figures, with a spokesperson saying: “The data upon which these claims are based is highly selective and does not capture Asda’s strong performance across George, Asda Express and fuel, which remain a key point of difference to the limited-range discounters.”

The competitive pressure is evident in Kantar’s latest published data, which showed Aldi recording its fastest sales growth since early 2024 at 6.7% year on year, while Asda was the only major supermarket to register falling sales, down 3.2%.

Despite the milestone, Hurley insisted that overtaking rivals was not Aldi’s primary focus. “That’s not a target for us,” he said. “Our focus is on what Aldi does best, and that’s offering unbeatable low prices and growing and scaling our business.”

Aldi announced plans to open 10 new stores in the next 14 weeks and refresh 30 existing locations, as part of a £650m expansion programme.

With more than 1,050 UK stores currently, Aldi expects to reach 1,090 outlets by Christmas as it opens 40 new stores throughout 2025. Hurley outlined similarly aggressive expansion plans for 2026 and 2027, with 40 new stores planned annually – a step up from the roughly 30 stores the chain has typically added each year recently.

The company has set a long-term target of 1,500 UK stores, suggesting years of continued expansion ahead.

The shifting supermarket landscape comes against a backdrop of rising grocery inflation, which hit 4.1% in the four weeks to May 18, the highest rate since February 2024. According to Kantar head of insight Fraser McKevitt, this level typically triggers changes in consumer behavior, potentially benefiting discount retailers like Aldi.