| Revenue | — | — | — |
| Net sales | 249.63a | 237.71a | 222.73a |
| Membership fees | 4.83a | 4.58a | 4.22a |
| Total revenue | 254.45a | 242.29a | 226.95a |
| Operating expenses | — | — | — |
| Merchandise costs | -222.36a | -212.59a | -199.38a |
| Selling, general and administrative | -22.81a | -21.59a | -19.78a |
| Operating income | 9.29a | 8.11a | 7.79a |
| Other income (expense) | — | — | — |
| Interest expense | -0.17a | -0.16a | -0.16a |
| Interest income and other, net | 0.62a | 0.53a | 0.21a |
| Income before income taxes | 9.74a | 8.49a | 7.84a |
| Provision for income taxes | -2.37a | -2.2a | -1.93a |
| Net income including noncontrolling interests | 7.37a | 6.29a | 5.92a |
| Net income attributable to noncontrolling interests | 0a | 0a | -0.07a |
| Net income attributable to Costco | 7.37a | 6.29a | 5.84a |