Chapter 6: Inventory Accounting and Cost of Goods Sold

The distinction between service-based and merchandising operations centers on the need to account for inventory purchases, sales, and the associated costs of moving goods. The chapter establishes that gross profit, calculated by subtracting cost of goods sold from sales revenue, serves as a critical performance metric before operating expenses are considered. Understanding inventory accounting requires familiarity with how purchase-related transactions are recorded, including freight costs, purchase returns, allowances, and discounts that collectively determine the net cost of purchases. Two primary inventory tracking systems form the foundation of inventory accounting: the periodic inventory system, which reconciles inventory at set intervals using the formula beginning inventory plus purchases minus ending inventory equals cost of goods sold, and the perpetual inventory system, which maintains continuous records through barcode scanning and software technology. The choice of inventory costing method significantly influences financial outcomes and tax liabilities. Four standard approaches exist for assigning costs to inventory and expenses: specific identification, which tracks individual item costs precisely; FIFO, which assumes the earliest purchased items are sold first; LIFO, which assumes the most recently purchased items are sold first; and weighted average cost, which distributes total acquisition costs evenly across units. The chapter emphasizes U.S. GAAP principles governing inventory reporting, particularly consistency in method selection, transparency in disclosures, and the lower-of-cost-or-market valuation rule, which requires reporting inventory at the lesser of its historical cost or current net realizable value. To assess operational efficiency, the chapter introduces three analytical tools: gross profit percentage reveals profitability before operating expenses; inventory turnover ratio measures how frequently inventory converts to sales; and days inventory outstanding quantifies the average holding period for merchandise. The gross profit method enables companies to estimate inventory values when physical counts are impractical, while the chapter addresses how inventory errors create cascading distortions across consecutive reporting periods, underscoring the importance of accurate inventory management for stakeholder decision-making.