Equivalent units of production is a term applied to the work-in-process inventory at the end of an accounting period. It is the number of completed units of an item that a company could theoretically have produced, given the amount of direct materials, direct labor, and manufacturing overhead costs incurred during that period for the items not yet completed. In short, if 100 units are in process but you have only expended 40% of the processing costs on them, then you are considered to have 40 equivalent units of production.
Equivalent units is a cost accounting concept that is used in process costing for cost calculations. It has no relevance from an operational perspective, nor is it useful for any other type of cost derivation other than process costing.
Equivalent units of production are usually stated separately for direct materials and all other manufacturing expenses, because direct materials are typically added at the beginning of the production process, while all other costs are incurred as the materials gradually work their way through the production process. Thus, the equivalent units for direct materials are generally higher than for other manufacturing expenses.
When you assign a cost to equivalent units of production, you typically assign either the weighted average cost of the beginning inventory plus new purchases to the direct materials, or the cost of the oldest inventory in stock (known as the first in, first out, or FIFO, method). The simpler of the two methods is the weighted average method. The FIFO method is more accurate, but the additional calculations do not represent a good cost-benefit trade off. Only consider using the FIFO method when costs vary substantially from period to period, so that management can see the trends in costs.
Example of Equivalent Units of Production
ABC International has a manufacturing line that produces large amounts of green widgets. At the end of the most recent accounting period, ABC had 1,000 green widgets still under construction. The manufacturing process for a green widget requires that all materials be sent to the shop floor at the start of the process, and then a variety of processing steps are added before the widgets are considered complete. At the end of the period, ABC had incurred 35% of the labor and manufacturing overhead costs required to complete the 1,000 green widgets. Consequently, there were 1,000 equivalent units for materials and 350 equivalent units for direct labor and manufacturing overhead.