Why is Costco's 2.1% operating margin on merchandise actually a profitable business?

Costco's financial statements look alien compared to traditional retailers. The company reports $275.2 billion in revenue for fiscal 2024 (ended September 1, 2024), but merchandise sales carry a gross margin of just 10–11% and operating margins on merchandise of 1–2%. Yet Costco is extraordinarily profitable because it has engineered a hybrid revenue model: merchandise sales are nearly break-even, but membership fees of $5.0 billion contribute 85–90% of operating income. This article decodes Costco's income statement, balance sheet, and cash flow statement, revealing how the company's warehouses are actually membership clubs that happen to sell goods, not retailers that happen to charge membership. Understanding this business model distinction is critical for investors evaluating Costco's financial health and long-term durability.

Quick definition: Costco's business model is membership-based wholesale. Customers pay annual or semi-annual fees to shop in the warehouses; Costco then sells merchandise at minimal markups (typically cost or cost+2–5%). The membership fees are pure profit, funding operations and generating shareholder returns. This is fundamentally different from Walmart or Target, which rely on merchandise markups for profitability.

Key takeaways

• Costco's $5.0 billion in membership fee revenue in FY2024 (separate from merchandise sales) is the hidden profit engine. On merchandise sales of $270.2 billion, gross profit is only $29.9 billion (11% margin), leaving minimal room for operating expenses. Membership fees bridge this gap, contributing ~85% of operating income.
• The company's consolidated statement of operations presents merchandise gross profit and membership fee revenue separately in the footnotes, but the 10-K requires careful reading to extract this; some investors miss the membership economics entirely and underestimate Costco's profitability.
• Operating expenses (SG&A) of $26.9 billion (9.8% of total revenues) are lean due to Costco's warehouse format (minimal staff per location, no fancy displays, no marketing). With efficient operations, the company converts membership fees almost entirely to operating income.
• Working capital is negative (Costco collects membership fees annually, collecting cash before delivering the service; suppliers extend payment terms), providing interest-free financing for growth and capital expenditures.
• Costco's net income margin of 2.3% ($6.3 billion / $275.2 billion) appears low compared to Walmart (2.4%) or Amazon (5.0%), but when measured on a comparable basis (including membership fees), Costco's true operating margin is closer to 4%, making it a high-quality compounder.

Revenue: $275.2 billion, split into two categories

Costco's consolidated statement of operations shows "Total revenues" of $275.2 billion, but this number combines two fundamentally different revenue streams: merchandise sales and membership fee revenue.

Merchandise sales: $270.2 billion (98.2% of total revenues). This is the revenue from selling goods in the warehouses: groceries, electronics, household items, gasoline, and more. Merchandise is the visible top line, and it grows steadily as Costco opens new warehouses and same-warehouse-sales (comparable sales or "comps") improve.

Membership fee revenue: $5.0 billion (1.8% of total revenues). This is the profit on memberships sold to customers. Costco charges:

• Gold Star membership (US): $65/year for individuals
• Executive membership (US): $130/year for businesses and power shoppers
• Similar fees in international markets (Canada, Japan, UK, Mexico, South Korea, etc.)

Costco has ~67 million members globally as of FY2024. At an average fee of ~$75 per member (blended across tiers and regions), $67M members × $75 = $5.0B, matching the disclosed membership fee revenue. The fee is the most transparent metric; it is collected upfront (or semi-annually), with minimal refunds (Costco's member satisfaction is so high that refund rates are ~1–2%).

The key insight: Costco's membership fee revenue has zero COGS. Every dollar collected in fees is gross profit. This is a fundamentally different economics than merchandise sales, where gross profit is only 11%.

Cost of merchandise sold: $240.3 billion

COGS on merchandise is $240.3 billion, leaving gross profit on merchandise of $270.2B − $240.3B = $29.9B, or 11.1% gross margin. This is far lower than Walmart (22–23%) or Target (26–27%).

Why does Costco accept such low merchandise margins? The answer is deliberate strategy:

1. Volume and member loyalty: By selling at near-cost, Costco attracts members and drives shopping frequency. A $65 annual fee is a sunk cost; once paid, members are incentivized to shop regularly to justify the fee. This drives high store traffic and, critically, high attach rates (members buy multiple items per visit, including impulse purchases with higher markups).

2. Limited SKU strategy: Costco carries only ~3,700 SKUs (stock-keeping units) in a typical warehouse, vs Walmart's 100,000+. This reduces inventory complexity, shrinkage, and operational overhead. The limited selection also means Costco can negotiate better terms with suppliers (higher volumes per item, lower costs).

3. Merchandise as a customer acquisition tool: Costco views merchandise not as a profit center but as a vehicle to drive membership adoption and retention. The low prices and high quality build loyalty; the merchandise is profitable when including the membership fee, not when viewed standalone.

4. Operational leverage on membership fees: As Costco grows revenues, membership fee income grows with it (more members, higher fees). But SG&A grows more slowly (a warehouse built in year one serves more members in year three). This creates leverage where incremental revenue flows largely to operating income.

Gross profit and gross margin

Costco's consolidated gross profit combines merchandise gross profit ($29.9B) and membership fee gross profit ($5.0B, since fees have zero COGS) for a total gross profit of $34.9 billion on $275.2 billion in revenues, or 12.7% gross margin.

This blended gross margin is misleading because:

• Merchandise gross margin is 11.1% (extremely thin)
• Membership fee gross margin is 100% (pure profit)

Investors must separate these mentally. A 12.7% blended margin suggests Costco is barely profitable; in reality, the company is highly profitable because the membership model subsidizes low merchandise margins. If Costco had a traditional retail model (relying on merchandise markups), it would be in trouble. But with the membership fee model, the company is thriving.

Operating expenses: $26.9 billion

Costco's SG&A expenses are $26.9 billion, or 9.8% of total revenues. This is the cost of running the warehouses: labor (store associates, managers, receiving staff), facilities (rent, utilities, maintenance), insurance, and corporate overhead. For context:

• Walmart's SG&A is ~20% of revenue
• Target's SG&A is ~21% of revenue
• Amazon's SG&A is ~15% of revenue

Costco's 9.8% SG&A is lean because of the warehouse format:

1. No frills, minimal labor: Costco warehouses are spartan; no fancy displays, limited staff (one cashier per line), minimal customer service. A typical warehouse has ~150–200 employees, vs a Walmart of similar size (100,000 sq ft vs 50,000 sq ft) with 300–400 employees.
2. No marketing: Costco spends almost nothing on advertising. The company relies on word-of-mouth and member referrals to drive growth. Walmart and Target spend billions annually on ads and promotions.
3. Supply chain efficiency: Costco owns its own supply chain and logistics, which is more efficient than outsourcing. The company also benefits from forward buying (purchasing items in bulk at off-peak prices) and directly importing from manufacturers.

The lean SG&A structure is a competitive advantage that Costco has maintained for decades. New competitors (Amazon Fresh, Whole Foods) have tried to replicate the warehouse model but have struggled to match Costco's efficiency.

Operating income: $8.0 billion

Costco's operating income is merchandise gross profit ($29.9B) + membership fee revenue ($5.0B) − operating expenses ($26.9B) = $8.0B, or 2.9% operating margin on total revenues.

But this is where the membership fee magic becomes visible: Of the $8.0B operating income, ~$5.0B comes from membership fees and ~$3.0B comes from merchandise operations. In other words:

• Membership fee contribution to operating income: $5.0B / $8.0B = 62.5%
• Merchandise contribution to operating income: $3.0B / $8.0B = 37.5%

This split reveals Costco's business model: merchandise is barely profitable, but membership fees fund the whole operation, allowing the company to offer rock-bottom merchandise prices and still be highly profitable overall.

Other income and expenses

Costco reported "other income, net" of $0.3 billion, which includes interest income on cash and investments. The company carries minimal debt (unlike Walmart or Target), so interest expense is negligible. Other income is immaterial to Costco's profitability, unlike Apple or Microsoft, where investment income can be significant.

Income tax provision: $1.8 billion and a 22.8% effective tax rate

Costco's income tax provision was $1.8 billion on pre-tax income of $8.3 billion (operating income $8.0B + other income $0.3B), for an effective tax rate of 22.8%, slightly above the 21% statutory rate. Costco pays more tax than some tech giants because the company is less aggressive with international tax strategies; most of Costco's operations are in the US, and the company is not heavily invested in IP licensing or transfer pricing structures.

An effective tax rate of 22–24% is reasonable and sustainable for Costco. The company does not have massive R&D credits or significant loss carryforwards, so future rates should remain near 22%.

Net income: $6.3 billion

Net income of $6.3 billion on $275.2 billion in revenue is a net margin of 2.3%. This looks thin, but it is actually healthy given the business model. Here is why:

The membership-adjusted profitability view: If we reframe Costco's revenues as "merchandise sales of $270.2B with a blended profit of 2.3%" plus "membership fees of $5.0B at 100% profit," we see that:

• Pure membership profit: $5.0B (collected upfront, recurring)
• Merchandise profit: $0.3B (residual)
• Total operating income: $5.3B (before taxes), or ~2% of merchandise sales

This is vastly different from a traditional retailer operating on 2% merchandise margins; Costco has a separate, highly profitable membership revenue stream.

Comparison to peers on an adjusted basis:

• Walmart: 2.4% net margin, but all from merchandise markups. Walmart has no membership revenue.
• Target: 2.0% net margin, all from merchandise markups.
• Costco: 2.3% net margin, but 60%+ is from membership fees (recurring, high-margin) and 40%− from merchandise (thin-margin, but high-volume).

When adjusted for the recurring membership revenue, Costco is actually more profitable than Walmart on an apples-to-apples basis. Walmart's 2.4% margin is all merchandise-dependent and cyclical; Costco's is part-merchandise and part-membership-dependent, with the membership part being more stable.

Operating income flowchart

Here is a visual showing how Costco's revenue flows to operating income:

Balance sheet implications of the membership model

Costco's balance sheet reveals the financial strength created by the membership model:

Current liabilities include large membership fee liabilities: Costco collects membership fees upfront (customers pay $65–130 for the year). The company records this as deferred revenue (a current liability) because it has collected cash but not yet delivered the service. As Costco delivers the membership benefit throughout the year, it converts the deferred revenue to revenue on the income statement. As of September 1, 2024, Costco's deferred revenue (mostly membership) was ~$2.5 billion, representing ~4 months of membership fee revenue already collected but not yet earned. This is a huge float; Costco gets cash now and records revenue throughout the year.

Negative working capital: Like Apple, Costco has negative working capital (current liabilities exceed current assets). This is a strength: Costco collects membership fees (a current liability, but soon to be revenue) and extends payment terms to suppliers (accounts payable is a large current liability). Both of these allow Costco to operate with minimal cash, using supplier and member financing to fund growth.

Cash flow statement insights

Costco's operating cash flow exceeds net income significantly, similar to Apple's model:

Operating cash flow: ~$12–14 billion (Costco's 10-K reports this; it is higher than net income due to non-cash depreciation, stock-based compensation, and the deferred revenue float).

Free cash flow: Operating cash flow minus capex. Costco opens ~25–30 new warehouses annually, requiring capex of ~$3.5–4 billion per year. This leaves free cash flow of ~$9–10 billion, which Costco deploys into dividends and buybacks.

The key insight: The membership fee model generates substantial cash upfront, which Costco uses to fund warehouse development without accessing debt markets. Costco's balance sheet is fortress-like with minimal debt, a rarity in retail.

Real-world comparisons: Costco vs traditional retailers

Walmart: Walmart generates revenue through merchandise markups, with minimal membership fees (though it offers Sam's Club membership, which is smaller and separate). Walmart's business model requires high inventory turnover and supplier leverage to achieve 2.4% net margins. Walmart is highly efficient but more dependent on merchandise pricing and SKU productivity.

Target: Target operates entirely on merchandise markups, with no membership revenue. Target's 2.0% net margin and recent margin compression (down from 3%+ pre-COVID) show the vulnerability of a merchandise-only model in a competitive environment. Target has been experimenting with a "Target Circle" membership to adopt a hybrid model, but it is nascent.

Amazon: Amazon has a membership model (Prime, $139/year in the US), but it is separate from Amazon's retail and marketplace operations. Amazon Prime revenue is not clearly itemized in the income statement, but it is estimated at $30–40 billion globally, with margins of 50%+. Amazon uses Prime membership to drive customer stickiness and loyalty, then monetizes through retail margins and advertising. This is similar to Costco but Amazon's primary profitability (before AWS) comes from advertising and marketplace take-rates, not wholesale merchandise.

Common mistakes when reading Costco's financial statements

Mistake 1: Assuming Costco's 2.3% net margin is low and concerning. Some investors see the 2.3% net margin and compare it unfavorably to Microsoft (35%) or Apple (24%), concluding Costco is a low-margin business. In reality, Costco's membership model creates a hidden 50%+ operating margin on membership fees. When adjusted, Costco's true profitability is much higher than raw net margin suggests.

Mistake 2: Assuming membership fee growth is limited. Costco can grow membership fees through:

• Adding new members in existing markets (US, Canada, Japan, etc.)
• Expanding into new markets (India, Eastern Europe, etc.)
• Raising membership fees annually (historically, Costco raises fees every 5–6 years; at 8–10% increases)
• Increasing the mix of higher-tier memberships (Executive members pay double)

Membership fee revenue is the fastest-growing segment at Costco, and it is highly profitable and recurring.

Mistake 3: Overlooking the deferred revenue float. Costco's $2.5 billion in deferred membership revenue is a source of interest-free financing. The company gets cash now and records revenue throughout the year. This reduces the need for working capital financing and allows Costco to be debt-free while growing rapidly.

Mistake 4: Comparing merchandise margins directly to competitors. Some analysts say "Costco's 11% merchandise margin is higher than some competitors' warehouse clubs," but this ignores Costco's $5 billion membership fee profit. The right comparison is total operating income, not merchandise margin alone.

Mistake 5: Underestimating Costco's competitive moat. Costco's network effects (more members drive more bargaining power with suppliers) and switching costs (members have paid upfront and are invested in the membership) create a deep moat. New entrants (Amazon Fresh) have struggled to replicate Costco's economics.

FAQ

Q: How much of Costco's profit comes from membership fees vs merchandise? A: Approximately 60–65% of operating income comes from membership fees ($5B), and 35–40% from merchandise operations ($3B). This means that if merchandise sales were completely unprofitable (zero profit), Costco would still be a $5 billion operating income company. This is the power of the membership model.

Q: What is Costco's true operating margin when adjusted for membership fees? A: Operating income of $8.0B / Total revenues of $275.2B = 2.9%. But if we separate the streams: membership fee contribution is $5.0B / $5.0B membership fee revenue = 100%, and merchandise contribution is $3.0B / $270.2B merchandise sales = 1.1%. The blended margin is 2.9%, but the membership portion is pure gold, while the merchandise portion is break-even.

Q: Can Costco raise membership fees without losing members? A: Yes, historically. Costco has raised membership fees every 5–6 years, typically at 8–10% per increase. Member retention rates remain above 90%, suggesting that customers perceive the value and are willing to pay higher fees. The next fee increase is likely in 2025–2026 (if it hasn't happened already), which would push Gold Star to ~$72 and Executive to ~$144.

Q: What is the risk to Costco's membership model? A: The main risks are: (1) Economic downturn reducing shopping frequency or member renewal rates; (2) New competitors (Amazon, Costco's ex-employees) launching rival wholesale clubs; (3) Suppliers reducing cooperation if Costco's leverage becomes too extreme; and (4) Merchandise deflation (prices falling), which would compress gross margins. However, Costco's member satisfaction is so high, and its supply chain is so efficient, that these risks are low.

Q: How does Costco's leverage strategy (low debt) compare to Walmart's? A: Costco carries minimal debt (near-zero) and funds growth through operating cash flow and membership fee float. Walmart carries moderate debt and uses it strategically to fund buybacks and acquisitions. Costco's conservative approach is lower-risk but may forgo some financial optimization opportunities. Both approaches are valid; Costco's is more conservative.

Related concepts

• Membership models and recurring revenue: Costco's model creates recurring, high-margin revenue that is less vulnerable to economic cycles than merchandise sales.
• Working capital float and interest-free financing: The membership fee float (deferred revenue) and supplier payment terms give Costco a substantial interest-free financing advantage.
• Operating leverage and scale: Costco's low SG&A (9.8%) means that incremental revenue flows largely to operating income, creating powerful operating leverage as the company grows.
• Merchandise margin vs operating income: A company can have low merchandise margins but be highly profitable due to other revenue streams (membership, advertising, etc.).

Summary

Costco's financial statements reveal a business model fundamentally different from traditional retail. While merchandise is sold at a slim 11% gross margin and generates only $3 billion in operating income, membership fees of $5.0 billion are collected upfront and converted almost entirely to profit, for a total operating income of $8.0 billion. This membership-first model, combined with lean operations (9.8% SG&A), fortress balance sheet (minimal debt), and powerful cash generation ($12–14 billion operating cash flow), creates a business that is far more profitable and durable than its 2.3% net margin suggests. For investors, the key is recognizing that Costco is a membership company that happens to sell merchandise, not a retailer that happens to charge membership. This distinction explains why Costco has delivered decades of consistent returns and is valued at a significant premium to traditional retailers despite seemingly lower profitability. The membership model is Costco's competitive moat, and it is becoming more valuable as the company raises fees and adds members globally.

Next

Read Costco's negative working capital advantage to see how the combination of membership floats, supplier terms, and inventory velocity creates a financial engine that funds growth without external capital.