Health experts commonly recommend that the average person should drink eight glasses of water per day which equals about 2000mL . This is called the 8×8 rule and is very easy to remember. Some health-care professionals recommend drinking milliliters for 1 pound of body weight. For example, if you weigh 140 pounds, you should drink 2072mL of water daily. Other factors that can affect how much water to drink per day include your physical activity level, your diet, certainly other health or medical factors, even the climate where you live.