Opencart's UPS shipping extension has a max cart weight. This fixes that issue by allowing you to determine what your max box weight will be. The total cart weight is then divided by the maximum weight to determine number of boxes and each boxes weight is calculated via UPS API.

For example: You have your max Box Weight set to 50 lbs and your total cart weight is 300 lbs this extension will take 300/50 = 6 boxes each weight 50 lbs and then will calculate the shipping rate for each box and total it up for the cart's UPS shipping cost.

Its also has the ability to add a box fee. Where in the example above if you had set a box fee of $5 it would have added 6boxes x $5 = $30 to the shipping total. We have only tested it on 1.5.X and 2.0.1. Other versions are at your own risk.

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