250 ml per 10 kg of body weight. Three glasses when you wake up - you've been all night without water . At least one glass 1/2 an hour before eating. This allows the body to absorb the water, treat and convert it back into the stomach ready for digestion. You also need to have mineral salts like celtic salt. Not rock or sea salt. Salt is needed to allow the water to enter into body cells. You need a level teaspoon per day.
Water is essential to your body. Not only does it help regulate body temperature, but also it assists in nutrient absorption, cushions organs and joints, helps remove waste from your body and moistens oxygen for better breathing. Water carries such important responsibilities; you may wonder how much of it the human body needs daily. Some people say that we should drink 8 glasses of water a day.......... For more detail http://ewhw.blogspot.com/2012/05/how-much-water-does-human-body-need.html
it does depend on how your body is feeling and its physical shape water provides energy for the white blood cells and red blood cells to breath for you so therefore the more outta shape you are the more energy need thus the more water at perfect size a third of a gallon a day