The GooglebaseXML product feed has various options for calculating for supplying shipping costs in your feed. These options are found on the shipping options tab, shown below.

There are three methods for handling shipping costs, depending on your choice for the Show Shipping option.

Supply Shipping Weight Only

You can choose to supply the shipping weight only, by selecting "No" for the Show Shipping option, and "Yes" for the Show Shipping Weight option. Then you can supply the shipping rates through your Google merchant centre dashboard, and Google will calculate the shipping costs for you.

Use Virtuemart Standard Shipping

If your store uses the Virtuemart standard shipping method by weight, ZIP and countries, then you can select this option for the Show Shipping option. That is all you need to do, the feed will automatically calculate the shipping costs for you. However you can also select exactly which shipping methods you want to display in the feed, which is normally a good idea.

Note that if you are supplying shipping costs then you must select a target country for the feed (on the basic options tab).

Calculate Using Rates

If your store uses some other shipping method, such as a 3rd party plugin, you can still supply the shipping costs in the feed, by supplying the rates. To do this, select "calculate using rates"  for the Show Shipping option.

You must first give a name to your shipping method, eg "Standard delivery by post".

Then you can supply either shipping based on the product value, or shipping based on weight, by clicking the "Select" button to bring up the rates dialogue, as in the image below.

The rates are created as repeatable fields, you can add or delete them using the plus and minus buttons. Note that you must supply the ranges in strictly ascending order of value. For example if you have varying rates for products worth up to $10, up to $20, and up to $30, then the rates must be listed in that order, because the feed will take the first one that applies. If none apply then the shipping cost will be assumed to be zero. So for example if you have a flat rate of shipping of $4.99 for orders up to a value of $30, then free shipping for orders above that, then you can set this very simply by setting $30 for "max product price", and $4.99 for the "shipping rate".

Remember to save your rates using the blue save button, then you must also remember to click the green save button (in the top left corner) for the GooglebaseXML options.

Note that if you are supplying shipping costs then you must select a target country for the feed (on the basic options tab).

Use a Custom Field

It is possible to use a Virtuemart custom text field to supply the shipping information. The custom field should be attached to the product in the normal way, and will contain the shipping cost. Then in the GooglebaseXML shipping options, select "Yes - use custom field" for the show shipping option.

Under the heading "Virtuemart Custom Field", supply a name for the shipping option, for example "standard delivery 3-5 days", and select the custom field that contains the shipping cost.

Note that if you are supplying shipping costs then you must select a target country for the feed (on the basic options tab).