Cost of goods sold (COGS) is calculated by adding up the various direct costs required to generate a company’s revenues. Importantly, COGS is based only on the costs that are directly utilized in producing that revenue, such as the company’s inventory or labor costs that can be attributed to specific sales. By contrast, fixed costs such as managerial salaries, rent, and utilities are not included in COGS. Inventory is a particularly important component of COGS, and accounting rules permit several different approaches for how to include it in the calculation.