Question: how many litres of water is 8 glasses equal to?
Answer: She points out that the "legitimate" organizations that perpetuate the myth, like Hydration for Health, have ulterior motives. They recommend 1.5 to 2 liters a day. (8 glasses measures out to 1.89 liters.) Danone, maker of bottled water, among other things, also happens to own the organization.