5 gal is how many oz?

One gallon has 4 quarts.

Each quart has two pints, so that is a total of 8 pints per gallon.

Each pint has 2 cups, so that is a total of 16 cups per gallon.

Each cup has 8 fl. oz. so that is a total of 128 fl oz per gallon.

Therefore, 5 gallons = 128*5 = 640 US fl. oz.

UK 20 fl. oz to the pint. 160 fl.oz. to a gallon.

Therefore, 5 gallons = 160x5 = 800 fl.oz. Imperial