Six Hundred and Ninety-Eight Million Square FeetWide moat

Walmart (WMT) — moat facet

The quietest moat there is: a catchment with enough business for one supercenter and not two.

Walmart's American selling floor comes to 698.7 million square feet: 633.7 million in 3,566 supercenters averaging 178,000 feet each, 36.6 million in 351 discount stores, and 28.4 million in 694 neighbourhood markets and smaller formats1. Sam's Club adds 601 clubs. Costco, the other large-format retailer in this collection, operates 134.7 million square feet2.

Walmart U.S. selling floor by format (million sq ft)Supercenters (3,566)633.7Discount stores (351)36.6Neighborhood markets (694)28.4Costco, for scale (914)134.7Walmart U.S. total 698.7m sq ft across 4,611 units; Costco operates 134.7m across 914.
Nearly seven hundred million square feet of American selling floor, five times Costco's. Efficient scale: a catchment with enough business for one supercenter will not pay for two.

Size on that scale stops being a description and becomes a physical fact about the country. A supercenter is a regional monopoly on a particular kind of shopping trip — the one where somebody buys groceries, a prescription, motor oil and a child's shoes in one stop — because the catchment that supports one of them will not support two. The economists call it efficient scale, and it is the quietest moat there is: nobody is kept out by a patent or a brand, only by the arithmetic of a second store in a town that has enough business for one.

The formats are not interchangeable, and that is deliberate. The supercenter is the profit engine and the pharmacy anchor. The neighbourhood market at 42,000 feet goes where a supercenter would be too big and a competitor would otherwise have the town to itself. Walmart has been adding to and remodelling the estate rather than expanding it much, which is what a company does when it believes the map is essentially complete.

The trade the floor space represents is worth stating plainly. A hundred and twenty thousand items in one building is an expensive way to sell groceries, and the hard discounters that carry two thousand items beat Walmart on a staples basket precisely because they are not paying for the other hundred and eighteen thousand. What Walmart buys with that cost is the trip itself: the customer who came for milk and left with a television, and the television is where the margin was.

Sales density is what settles it. Walmart U.S. did about $104.7 million of net sales per store in fiscal 20263. That figure is what converts square footage from an expense into an advantage, and it is the first thing that would move if the supercenter stopped being the default trip.

Moat trajectory: Holding steady

The American map is essentially drawn. Walmart has been remodelling rather than expanding, which is the right answer for a network this dense, and efficient scale does not erode: the catchment that supports one supercenter still will not support two. What moves is density rather than footprint.

The number that tests this moat
Moat Explorer calc
Walmart U.S. selling floor
698.7 million square feet

633.7 million in 3,566 supercenters, 36.6 million in 351 discount stores and 28.4 million in 694 small formats, against Costco's 134.7 million. The figure only matters through density; watch net sales per store rather than the footprint, which is essentially fixed.

Source: Moat Explorer calculation from the Item 2 Properties table ↗
⚠ Threats to the moat
⚠ THREAT 01
The Trip Is the Product, and Trips Are Getting Shorter
A hundred and twenty thousand items only pays if somebody walks past most of them, and an online order never wanders.
References
  1. Moat Explorer calcWalmart's American selling floor comes to 698.7 million square feet: 633.7 million in 3,566 supercenters averaging 178,000 feet each, 36.6 million in 351 discount stores, and 28.4 million in 694 neighbourhood markets and smaller formats.
    Moat Explorer calculation from figures in Walmart's own filings: global eCommerce of about $150.4 billion (Walmart U.S. $99.6B + International $35.8B + Sam's Club $15.0B) against $120.9 billion, a $29.5 billion increase against a $31,875M rise in net sales ($706,413M against $674,538M), about 92%; Walmart U.S. selling floor of 698.7 million square feet (633,724 + 36,609 + 28,375 thousand) and net sales per store of $104.7 million ($482,975M over 4,611 stores); operating margin 4.18% ($29,825M/$713,163M) against 4.31% ($27,012M/$648,125M); net margin 3.07%; gross profit rate 24.2% ($171,018M/$706,413M); grocery 59.1% of Walmart U.S. net sales ($285,482M/$482,975M) against 59.8% ($264,210M/$441,817M) and grocery growth of 3.4%; general merchandise to grocery ratio 0.40 against 0.43; health and wellness +26.7% ($54,898M to $69,547M); payables less inventories $4,210M ($63,061M less $58,851M); rent 0.34% of revenue ($2,434M/$713,163M); capital expenditure 64% of operating cash flow ($26,642M/$41,565M); a 1% overrun on $147,943M of expense is $1,479M; eCommerce penetration 27.5% international ($35.8B/$130,423M) and 20.6% at Walmart U.S. ($99.6B/$482,975M); shareholder returns $15,587M ($7,507M dividends plus $8,080M repurchases) against $14,923M of free cash flow; Q2 FY2027 net income attributable down 9.4% ($6,366M against $7,026M); Walmart U.S. comparable sales of about 3.9% excluding the 125 basis point pharmacy headwind — FY2024-Q2 FY2027 · publ. September 2026 · source ↗
  2. ReportedCostco, the other large-format retailer in this collection, operates 134.7 million square feet.
    Costco Form 10-K, fiscal year ended August 31, 2025 - Item 1 Business (membership counts and renewal rates, warehouse and gas-station counts, under 4,000 SKUs, Executive tier and the 2% reward, human capital and wages, competition, Kirkland Signature) — FY2025 · publ. October 8, 2025 · source ↗
  3. Moat Explorer calcWalmart U.S. did about $104.7 million of net sales per store in fiscal 2026.
    Moat Explorer calculation from figures in Walmart's own filings: global eCommerce of about $150.4 billion (Walmart U.S. $99.6B + International $35.8B + Sam's Club $15.0B) against $120.9 billion, a $29.5 billion increase against a $31,875M rise in net sales ($706,413M against $674,538M), about 92%; Walmart U.S. selling floor of 698.7 million square feet (633,724 + 36,609 + 28,375 thousand) and net sales per store of $104.7 million ($482,975M over 4,611 stores); operating margin 4.18% ($29,825M/$713,163M) against 4.31% ($27,012M/$648,125M); net margin 3.07%; gross profit rate 24.2% ($171,018M/$706,413M); grocery 59.1% of Walmart U.S. net sales ($285,482M/$482,975M) against 59.8% ($264,210M/$441,817M) and grocery growth of 3.4%; general merchandise to grocery ratio 0.40 against 0.43; health and wellness +26.7% ($54,898M to $69,547M); payables less inventories $4,210M ($63,061M less $58,851M); rent 0.34% of revenue ($2,434M/$713,163M); capital expenditure 64% of operating cash flow ($26,642M/$41,565M); a 1% overrun on $147,943M of expense is $1,479M; eCommerce penetration 27.5% international ($35.8B/$130,423M) and 20.6% at Walmart U.S. ($99.6B/$482,975M); shareholder returns $15,587M ($7,507M dividends plus $8,080M repurchases) against $14,923M of free cash flow; Q2 FY2027 net income attributable down 9.4% ($6,366M against $7,026M); Walmart U.S. comparable sales of about 3.9% excluding the 125 basis point pharmacy headwind — FY2024-Q2 FY2027 · publ. September 2026 · source ↗
Sources
Generated September 22, 2026