I love the theatre http://madthumbs.fun/ mad thumb • Initially, I recommend drinking at least half a gallon a day, but it's smart to try for more. It's hard at first, but you'll find that it gets easier the more you drink up. To get going, here's my favorite formula: Take your body weight, divide it in half and drink that number in ounces. For example, if you weight 150 pounds, half your weight is 75. So, you should aim to get 75 ounces of water a day. This is my best advice. Why? Because we're not all the same size, shape and weight. It wouldn't make sense for a 220-pound man and 130-pound woman to both drink 60 ounces of water a day. You could also follow the "8 by 8" rule (drinking at least eight 8-ounce cups a day), but there's a good chance it won't meet your individual requirement.