Gigacalories to gigawatt hours converter above calculates how many gigawatt hours are in 'X' gigacalories (where 'X' is the number of gigacalories to convert to gigawatt hours). In order to convert a value from gigacalories to gigawatt hours (from Gcal to GWh) just type the number of Gcal to be converted to GWh and then click on the 'convert' button.