12 x 12 x 6 12 x 12 x 12 14 x 14 x 18 14 x 6 x 6 16 x 12 x 10 24 x 24 x 18
Most of our orders are 2 - 7 pieces of somewhat random size and shaped items. We found it was considerable cheaper to use peanuts, paper or air pouches to fill the empty space vs more box sizes. We now by the boxes by the pallet per size and have a smaller storage area.
we ended up ordering custom boxes so that we could do the same consolidation. The intial dies were a little pricey, but we ended up saving a huge amount on the packing material we used to need to fill empty space.
And it seems that cardboard is a competite business, and it really paid to shop around a little.
So much of determining sizes is based on the products you carry. What I did was go back and look at my orders for the last 60-90 days. I then calculated what would have been the best size to pack the orders in. I also looked at how many orders were multiple products and how this impacted packing. My general goal in doing this was to avoid excess void fill, and also to be mindful of dimensional weight problems for UPS next day, 2nd day, and 3 day shipping.
One of the outcomes of this is I ended up with a new size box (16x6x4) which is now my most popular to use. This replaced an 18x6x6 box. Some of my other standards are 10x8x6, 12x12x6, 18x14x4, and 20x6x6.