Opening inventory = Ending inventory + COGS – purchase or additional units

Opening inventory, also known as beginning inventory:

is the merchandise or materials available at the begging of the period.  It can be a finished good like a shirt, or it can be processing materials like wool or cotton.

Having a lot of it available means that it might not be necessary to get more, it could mean that there weren’t many sales in the previous period, or more production than sales, etc.

Purchase or additional units= the period’s additional merchandise or materials

COGS: cost of goods sold =unit price-units sold

Ending inventory: the available units that companies have left in storage after COGS at the end of the accounting period = COGS- beginning inventory-purchases