How many 8 ounce cups in a gallon?

16 bottles. There is 128 ounces in a gallon, so you divide 128 ounces by 8 ounces in a bottle to get 16. Another way to think about it is 8 goes into 128 16 times, therefore you will need 16 8 ounce bottles to make a gallon (128 ounces).