Is it cheaper to buy groceries at Costco or Walmart?

Generally, Costco is cheaper per unit for groceries—especially bulk staples, meat, dairy, frozen foods, pantry items, and household basics. In fact, a 2026 price comparison of identical grocery items found that Costco was about 21.4% less expensive on average than Walmart.

However, Walmart is often cheaper in practice for shoppers who buy smaller quantities, want to avoid paying a yearly membership fee, or don't have the space to store bulk packs.

The bottom line: If you can use bulk sizes before they spoil and shop enough to offset the membership fee, Costco will save you more money overall. If you prefer smaller portions, want to minimize upfront spending, or have limited storage, Walmart is often the more practical and cost-effective choice for your day-to-day budget.