Grams per cup to ounces per gallon (US) conversion calculator shown above calculates how many ounces per gallon (US) are in 'X' grams per cup (where 'X' is the number of grams per cup to convert to ounces per gallon (US)). In order to convert a value from grams per cup to ounces per gallon (US) (from g/cup to oz/gal) just type the number of g/cup to be converted to oz/gal and then click on the 'convert' button.