Gigawatt hours to watt seconds conversion calculator shown above calculates how many watt seconds are in 'X' gigawatt hours (where 'X' is the number of gigawatt hours to convert to watt seconds). In order to convert a value from gigawatt hours to watt seconds (from GWh to Ws) type the number of GWh to be converted to Ws and then click on the 'convert' button.