how much water is 2/3 cups of water

Well, there are 8 ounces in a cup. So 2/3 can be figured like this: Convert 2/3 to .66. With 100 as a whole, 1/3 is .33 so 2/3 is .66. 8 X .66 is 5.28. 5.28 ounces is an accurate answer, which is almost the amount in a small glass bottled coca cola.