Megawatt hours to gallon-atmosphere (UK) conversion calculator shown above calculates how many gallon-atmosphere (UK) are in 'X' megawatt hours (where 'X' is the number of megawatt hours to convert to gallon-atmosphere (UK)). In order to convert a value from megawatt hours to gallon-atmosphere (UK) (from MWh to gal atm) simply type the number of MWh to be converted to gal atm and then click on the 'convert' button.