When a customer makes a purchase in your store, the store must calculate the price to ship the item to the customer in order for the customer to be charged this amount in checkout. There are two options for calculating shipping costs in your store, online APIs and flat rates.
Your store uses three shipping APIs to obtain live rates from the top shipping providers right in your cart. When the customer is checking out of the store, the store will send the weight and dimensions of the package, where it is going and where it is coming from to the shipping provider who responds with up to the minute rates for shipping that package. The customer can then choose the different shipping methods available for this package and proceed with checkout. Your store can obtain live rates from UPS, FedEx and USPS. The links below give more information about each solution and descriptions on integrating the solution with your store.
Flat rates allow the store owner to set up shipping rate scales based on weight, price or region. For more information on setting up shipping rate scales see link below.
NOTE: You can use more than one calculated method in your store based on the destination of the shipment. Once you have activated the shipping rates you intend you use, you can determine which rates to use for which destinations in the Method Selection section.