Top 10 Costco Competitors (2026): Who's Really Winning

Costco built its empire on rock-bottom bulk prices and a fee-based membership model, but no discount retailer owns wholesale forever. This list of the top 10 Costco competitors breaks down who is actually challenging its roughly 62% share of the U.S. warehouse club market, from Sam's Club to Amazon, and why some rivals matter far more than others.

What Are Costco's Top Competitors?

Costco's competitors fall into three groups. The first is direct warehouse clubs that copy its membership model: Sam's Club and BJ's Wholesale. The second is mass retailers that sell similar bulk and grocery goods without a membership fee, led by Walmart, Target, and Kroger.

The third group is digital and niche disruptors. Amazon, through Prime and Amazon Business, competes for the same bulk-buying household without a warehouse trip. Aldi, Trader Joe's, Restaurant Depot, and Grocery Outlet each chip away at a specific slice of Costco's grocery and small-business customer base.

Costco Competitors Explained: Market Share and Positioning

Costco reported $286.3 billion in trailing twelve-month revenue as of February 2026, up 8.4% year over year, with a market cap near $477 billion and 921 warehouses worldwide. Its membership renewal rate sits at 89.7%, among the highest in retail.

Sam's Club holds roughly 31% of the U.S. warehouse club market and BJ's Wholesale about 7%, leaving Costco with the remaining 62%. That gap has widened since 2022, when Costco held 55.5% against Sam's Club's 36.2%, according to industry data.

The structural reason for that gap comes down to the economies of scale definition every retail analyst uses, covered in more depth in our business concepts hub: as a company grows purchase volume, its per-unit cost of goods, shipping, and warehousing falls, letting it pocket the margin or pass savings to members.

Recent moves show how tight the rivalry has become. In April 2026, Costco paid members a $12-per-share special dividend, a $5.3 billion cash return read across the industry as a show of strength. Weeks later, Sam's Club raised its base membership fee for the first time in three and a half years, lifting Club to $60 and Plus to $120.

The Top 10 Costco Competitors

The ranking below orders competitors by how directly they challenge Costco's core business: bulk goods, low per-unit pricing, and a loyal, recurring customer base. Some fight Costco warehouse to warehouse. Others chip away one grocery trip or one Amazon order at a time.

1. Sam's Club

Owned by Walmart, Sam's Club is Costco's most direct competitor and the only rival that matches its membership-fee, bulk-pricing format at national scale. It holds about 31% of the U.S. warehouse club market and just raised its own fees to $60 for Club and $120 for Plus in May 2026.

2. BJ's Wholesale Club

BJ's undercuts both Costco and Sam's Club on membership price and often runs deeper grocery discounts, up to 25% versus supermarkets. Its trade-off is a smaller, more regional footprint concentrated on the U.S. East Coast, which caps how much share it can realistically take.

3. Walmart

Walmart's core supercenters compete with Costco without any membership fee at all, betting on sheer scale and store count instead. With a market cap above $1 trillion, Walmart is Costco's biggest publicly traded rival by valuation, more than double Costco's own.

4. Target

Target competes less on bulk pricing and more on convenience, style, and a stronger private-label lineup than Costco offers. It wins shoppers who want a quick, curated trip rather than a cart built for a month of groceries.

5. Kroger

Kroger, the largest traditional U.S. supermarket chain, competes on proximity and weekly grocery pricing rather than bulk packs. Rising food prices have pushed some Kroger shoppers toward warehouse clubs, but Kroger's loyalty and fuel-discount programs keep plenty of them from switching entirely.

6. Amazon

Amazon competes with Costco without a warehouse at all. Prime subscriptions and Amazon Business both offer bulk ordering and fast delivery, letting shoppers skip the drive for a large share of what they would otherwise buy on a Costco run.

7. Aldi

Aldi, the privately held German discounter, undercuts nearly everyone on grocery price through a stripped-down, no-frills store format and heavy private-label stock. With almost 2,800 U.S. stores, it is excluded from public competitor rankings but genuinely takes grocery share from Costco.

8. Trader Joe's

Trader Joe's competes on a curated, private-label product mix rather than raw bulk savings. Its cult following draws shoppers who want quality and novelty over the biggest possible pack size, a very different pitch than Costco's.

9. Restaurant Depot

Restaurant Depot targets the small-business and restaurant buyer Costco also courts through its Business Center locations. It sells strictly to license-holding businesses, competing directly for bulk food-service accounts rather than household shoppers.

10. Grocery Outlet

Grocery Outlet sells closeout and surplus goods at steep discounts, appealing to bargain hunters who prioritize price over selection or brand consistency. It rarely competes head-on with Costco but does pull budget-focused grocery trips away from every rival on this list.

Costco's toughest competitor isn't the store next door. It's the shopper who stopped needing a warehouse trip at all.

How to Compare Costco Competitors on the Numbers

Ranking these rivals by store count only tells half the story. Investors and operators comparing Costco competitors also look at a handful of core accounting metrics that expose which business model actually holds up.

Gross Margin

Gross margin definition: the percentage of revenue left after subtracting the cost of goods sold. Gross margin meaning in this context is simple: Costco runs a famously thin gross margin, often near 12-13%, because it prices to sell memberships, not markup. Rivals like Target run far higher gross margins but sell fewer units per shopper visit.

Working Capital and Cash Flow

Working capital definition: current assets minus current liabilities, a measure of a company's short-term financial cushion. Cash flow definition: the actual cash moving in and out of a business, separate from reported profit. Costco's membership fee income, collected upfront, gives it stronger working capital and cash flow than most grocery rivals relying purely on thin daily sales.

Balance Sheet Strength

Balance sheet definition: a snapshot of a company's assets, liabilities, and equity at one point in time. Balance sheet meaning for a retailer like Costco centers on real estate, warehouse infrastructure, and inventory. A strong balance sheet lets a chain like Walmart absorb a bad quarter that would sink a smaller regional rival.

Depreciation

Depreciation meaning: the gradual reduction in the recorded value of a physical asset over its useful life. Depreciation definition in retail terms covers warehouses, refrigeration units, forklifts, and delivery fleets, all of which lose book value every year they are used. A competitor building fewer, larger warehouses, like Costco, carries a different depreciation load than one running many small stores, like Trader Joe's.

Overproduction and Inventory Risk

Overproduction in retail shows up as excess inventory bought or stocked beyond what shoppers actually buy. Bulk retailers face a sharper version of this risk than regular grocers, since a pallet of unsold goods ties up far more cash and shelf space than a single case. Costco manages this with a famously narrow product selection, stocking roughly a tenth of the items a typical supermarket carries.

Accounts Receivable

Accounts receivable definition: money owed to a business by customers who bought on credit rather than paying immediately. Accounts receivable meaning barely applies to Costco itself, since its consumer sales are cash-and-carry, but it matters far more for a B2B rival like Restaurant Depot, which extends credit terms to restaurant and business accounts.

The Threats Costco Still Has to Watch

Amazon is the clearest long-term risk. Every bulk order placed through Prime or Amazon Business is a small act of reintermediation, a new middleman inserting itself between Costco's model and the household budget it used to own outright.

Self-checkout, AI-driven inventory forecasting, and curbside pickup all count as innovation Costco and its rivals are racing to adopt. Getting the benefits and risks of innovation wrong, either by moving too slow or spending too fast, can erase a cost advantage built over decades.

For any retailer on this list, ignoring e-commerce or membership fatigue is a corporate version of the signs you're being set up to fail at work: warning signals visible well before the numbers actually turn.

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Top 10 Costco Competitors: FAQ

Who is Costco's biggest competitor?

Sam's Club, owned by Walmart, is Costco's biggest and most direct competitor, running the same paid-membership warehouse model and holding about 31% of the U.S. warehouse club market.

What is working capital?

Working capital is current assets minus current liabilities, showing whether a company has enough short-term resources to cover its near-term bills. Costco's upfront membership fees give it stronger working capital than most pure grocery rivals.

What is gross margin?

Gross margin is the percentage of revenue left after subtracting the cost of goods sold. Costco runs one of the thinnest gross margins in retail, often near 12-13%, because membership fees, not markup, drive its profit.

What is accounts receivable?

Accounts receivable is money a business is owed by customers who bought on credit instead of paying immediately. It matters little for Costco's cash-and-carry consumer sales but matters more for B2B rivals like Restaurant Depot.

What does a balance sheet example look like?

A balance sheet example lists assets like cash, inventory, and warehouses on one side, and liabilities like debt and accounts payable on the other, with the difference shown as equity. Costco's balance sheet is heavy on owned real estate and light on receivables.

What does a profit and loss statement example show?

A profit and loss statement example lays out revenue, cost of goods sold, operating expenses, and net profit for a set period. Comparing Costco's and Sam's Club's statements side by side shows how membership fee income boosts Costco's bottom line even on thin merchandise margins.

Sources: Warehouse club (Wikipedia), U.S. Census Bureau retail trade data.