Equivalent units of production are the work done during the period on the physical units of output, expressed in terms of fully completed units. Equivalent units of production are determined by applying the percentage of work done to the physical units of output. Equivalent units are the sum of the work performed to: 1 Finish the units of beginning work in process inventory. 2 Complete the units started into production during the period. 3 Start, but only partially complete, the units in ending work in process inventory.