it doesnt really work like that lol.... fl oz is a measurement of volume... a more dense liquid will have more mass than a less dense, grams measure mass... you would need to weigh 29.6 ml (aka a fluid oz) of whatever you want to know the gram weight of lol
Water weighs about 7 pounds per gallon 8 for salt and there's 153 oz in a gallon so and there's 453 grams in a pound so a gallon weighs 3,171 grams now devide that by 153 and you get 20.3 grams per fl oz of h20 but idk about alcohol