How does shipping cost get calculated in shopping carts?

My shopping cart software (Volusion) calculates the shipping charge by using my UPS account, plus any handling fee we want to add. Or it can be done on a weight basis. If your box is over the "Dimensional Weight" threshold, be careful not to overlook the cost of sending a large box. Here is how you calculate "dimensional weight": multiply in inches width x depth x height of the box. Then divide by 194. That number is the "dimensional weight". UPS and FEDex use the larger of "dimensional weight" or "actual weight". I would recommend finding which one is bigger, then typing that into your shopping cart as the "weight" of the product. That way you won't come up short.

By getting an account with UPS, you automatically get 40% off retail rates. You get a "daily pickup" rate. You can get setup for a daily pick up rate, and cancel the actual pickup while maintaining the good rate. Just open the account, and then call them to say you don't want the truck coming by every day.