When generating Google Shopping Feeds you need to make sure to use the correct currency for the target country. Thus, if you are planning for instance to target Great Britain make sure to use GBP as currency for prices in the Products Feed. This can be easily achieved by using the Magento extension Wyomind Data Feed Manager. It will automatically convert from the default currency currently set to the one specified in the product pattern configuration.
Enable conversion currencies
Automatic currency conversion for Products Feed
In order for the automatic conversion to work you need to ensure that built-in the conversion web service ran at least once. Thus, either run the web service manually or better set it up to run on a regular basis through your cron setup: The Data Feed manager currency conversion will work properly once the initial conversion rate data is available. Make sure to update the conversion rates on a regular basis!
Syntax for price conversion
In order to use the price conversion in the Data Feed manager use the following syntax:
This will convert the default currency set to GBP based on the current conversion rates determined by the web service. Have a look at the Wyomind Data Feed Manager documentation for more information on how to use this extension.