This is an easy solution for people that want an easy way to do box level inventory for Amazon FBA but don't want to pay a month fee for a service to it.
This method uses the Excel sheet option in Seller Central along with a hand scanner. ****Note, you must have a hand scanner to make this work
This method lets you actually scan each item as it is put into a box, so there is no guessing on how much will fit into a box.
Other "solutions" still require you to guess what will fit in each box which is not really a solution. This is the equivalent of using a pen and paper to mark what you put in each box except it is faster and more accurate.
This comes with 3 training videos showing how to use this system and 1 Excel template that can be used with Excel, OpenOffice or Google Drive Sheets.
This is a 1 time fee and makes box level inventory very simple to do.