The most appropriate inventory accounting method for calculating COGS depends on a company's specific inventory turnover and operational structure. Common methods include FIFO (First-In, First-Out), LIFO (Last-In, First-Out), and the Weighted Average Cost method. FIFO is often favored during inflationary periods to reflect current asset values on the balance sheet, whereas LIFO matches recent higher costs with current revenues for tax reduction purposes where permitted.