Using the CBM (cubic meters) field in Inventory Planner, you can add information about the volume of your product. This can be used to calculate volume of an order to fill a container for shipment.
In Replenishment, add CBM using 'Columns' at the top of the page.
Then select the CBM column and click Apply.
Then you'll have a field in that column where you can enter information.
Finally, save your changes.