I want to be able to convert a box of 4 units of Item B into 4 individual units of that Item B.

Example:

In my purchase order to our supplier I specify 10 boxes (each with 4 units/box) of Item B. However, as I sell Item B by the unit, I need the inventory to reflect 40 units of Item B and not just 10.

Right now, I am doing this conversion manually. However, will there be any feature to make this conversion between multiple units of measurements? (boxes, cases, bags -> units)

Thanks in a advance.