I use the following calculator because you can keep it open whilst you browse ebay: >>XE Currency Converter<<
All USPS Rates are here: >>
USPS International Postage Rates & Fees<<
All German Rates are here on the worlds worst designed web site (bar none - 8 levels of navigation to get here!):>>
Parcels up to 2 kilos<<
UK rates are divided up between the Royal Mail - (on the worlds slowest web site!)
Small packets only
and ParcelForce >>Tariff Download Centre<<
Hope this helps