Enter the beginning inventory and the ending inventory into the Calculator. The calculator will evaluate the Average Inventory. This calculator can also determine the beginning or ending inventories when given the other variables.

Average Inventory Formula

The following two example problems outline the steps and information needed to calculate the Average Inventory.

AI = (BI + EI) / 2


  • AI is the Average Inventory (units)
  • BI is the beginning inventory 
  • EI is the ending inventory 

To calculate Average Inventory, sum the beginning inventory and ending inventory values, then divide by 2. 

How to Calculate Average Inventory?

The following steps outline how to calculate the Average Inventory.

  1. First, determine the beginning inventory. 
  2. Next, determine the ending inventory. 
  3. Next, gather the formula from above = AI = (BI + EI) / 2.
  4. Finally, calculate the Average Inventory.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

beginning inventory = 30

ending inventory = 100

AI = (BI + EI) / 2 = ?