A new report from research firm Numerator highlights the continuing dominance of Walmart in the U.S. grocery sector, where the retail powerhouse commands more than 20% of total food spending. In practical terms, one out of every five dollars spent on groceries is directed into Walmart’s tills—an achievement that underscores the company’s unrivalled scale, reach, and pricing power.
Yet the real intrigue lies further down the rankings. Kroger, with an 8.9% market share, has edged ahead of Costco, which holds 8.5%. Though the margin may seem marginal, its significance is considerable: it marks Kroger’s ability to withstand the aggressive growth trajectory that Costco has sustained in recent years.
For Kroger, the second-place position represents not only a strategic victory but also a reaffirmation of its ability to compete effectively in a fiercely contested marketplace. Costco’s model of membership-based bulk purchasing has long posed a threat, appealing to price-sensitive shoppers eager to cut costs amid inflationary pressures. Despite this, Kroger’s extensive network, emphasis on fresh produce, and loyalty-driven promotions have given it an edge in retaining customer trust.
Analysts suggest that the Kroger–Costco rivalry will intensify as consumers continue to adapt their shopping habits. Costco’s membership appeal and value-driven offers remain strong, while Kroger’s continued investments in technology, private labels, and digital engagement ensure it remains highly competitive.
What remains clear is Walmart’s unshakeable position at the top of the grocery hierarchy. Its dominance, supported by scale and low pricing, shows little sign of waning. For Kroger and Costco, however, the contest for second place could prove decisive in shaping the next chapter of U.S. grocery retail.