Note: Fiscal year for Costco ends on the Sunday nearest to the end of August. (E) denotes an estimate based on the latest available trailing twelve months data.

Costco's gross margin has shown some fluctuation over the past five fiscal years. After peaking at 13.1% in 2020, it saw a decrease in 2021 to 12.9% and a further dip to 12.2% in 2022. The margin recovered slightly to 12.3% in 2023 and continued to improve to 12.6% in 2024. For the 2025 fiscal year, the gross margin is estimated to be around 12.8%, based on the performance in the first three quarters and the latest trailing twelve months data. The company's strategy of maintaining low prices and high sales volume contributes to these margin levels.