Multiple Food Product Shipping

So I have been struggling for a month now trying different shipping scenarios with no luck. We sell beef and never know how many cuts of beef a customer will order and so how big a box we will need. For example, a customer may buy a Rib Eye Package which includes “2” 11 oz rib eyes and 4 lbs of ground beef. We also include 4 ice bricks at 1 lb each and a small box for this order weighs 2.5 lbs (15x14x13) The total weight of the order is 11.875 lbs.

So let’s say the customer adds a T-Bone Steak Package to the order. Each steak (2) weighs 14 oz and includes 4 lbs of Ground Beef. To ship this order we would increase the box size to 21 x 14 x 12 and that weighs 3 lbs and 2 more ice bricks. Thus if we add it to the Rib Eye Package the total is now 20 lbs.

So how do I set up shipping so that UPS knows whether it is a smaller box or a larger box determined by the number of items in the box AND that the number of items in the box have increase the weight as well.

Please help, this is really stumped me!

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