The healthy consumption of water can be estimated this way. You can get your weight, and then divide it in half. So, for example, say someone was 90 pounds. 90 divided by 2 would be 45. That's how many cups of water that person should drink that is healthy. I heard this from a teacher at school, and he was explaining why he allowed water in his computer class. :)
This answer comes from Web MD: The Institute of Medicine released revised standards for hydration a few years ago. After factoring in water intake from fruit and vegetables, they recommend men drink ~13 glasses/day (100 oz) and women ~9 glasses (72 oz). Other things to consider: exercise and your weight/height.
Here is something else from Web MD: When you drink huge amounts of water (in one sitting), you flush out sodium, potassium, and other essential electrolytes. Kidneys overload. Cell membranes rupture from osmotic pressure. The brain swells with edema. Headaches, nausea, disorientation, and dizziness occur, followed by seizures and coma. Death can soon follow. That's why water drinking contests are so dangerous!
It depends on what is your location. A man in Moscow, London or in needs much less less water than a man residing in Africa or Rajasthan (India). As per normal 4 to 6 litre water is enough for us (Indians)
A person should drink AS MUCH WATER AS IT TAKES TO QUENCH YOUR THIRST. In an ideal world the first drink of the day should be sparkling pure fresh water. I generally wash all of my psychotropic & other pharmaceuticals down with a gulp or 2 of bottled water. Most persons without a diagnosis of Type 1 or Type 2 diabetes, formerly known as juvenile or adult-onset diabetes, will have increased thirst & frequency of urination.
Most doctors will say shoot for (8) 8 oz glasses per day or 64 0z. Alot depends on your activity, the weather, your size, etc. A good guide for a normal day would be about half of your actual weight in oz. say your 120 lbs....drink 60 oz...if your 240 lbs then about 100 oz. it need not be exact but very close. Then increase intake with activity, weather, etc to allow for sweating, etc. A few years ago a radio station in our state ran a contest to see which listener could drink the most waterto win some sort of tickets, checking in on them every hour or so....well, a younger mother died from doing this!! WHY? Because there is a real problem called water intoxication or (hyponatremia), that can cause a range of problems, even death and apparently the station and the mother knew nothing about this when they started the idiotic contest!!!!. Everything in life is good, even great........ in moderation!!! Read up on HYPONATREMIA!!!!!!!!
Actually, the recommended quantity of water you need to drink differs according to age, body weight and physical activity. The weather also plays a role in your water needs. Children (one year and above), usually require about 0.8 to 1.4L per day depending on their age. It is important that you make it a regular habit. For adolescents, at least 1.6 Liters per day. But remember, with more physical activity, the requirement will increase. For adults the amount ranges between 1.5 and 2 Liters per day, which is equivalent to 8 glasses of water. Regularly drinking water is essential when exercising. It is recommended that you drink 1 glass of water prior to exercise, and half a cup every 20 minutes throughout your workout( http://goo.gl/mm0tIf ). After finishing, try to drink water or fluids to compensate for the water lost from your body, especially if you were having an energetic workout. If you are on a diet, it is important to remember that an increase in your intake of water is necessary.