How Much Water Should You Drink? This simple calculation can help you estimate how much water you should drink each day to stay adequately hydrated: Simply divide your weight in half. Thus, a 135-pound person should drink 67.5 ounces of water a day. Divide this by 8 and you get 8.43. Rounding this number, a 135-pound person should drink 8, 8-ounce glasses of water a day.
Keep in mind that any calculation doesn’t take into account your unique circumstances, such as exercise, climate, pregnancy, and so forth. Use the above calculation as a starting point, and fine-tune your requirements by noticing the color of your urine. If you’re adequately hydrated, your urine should be clear and colorless. If it’s gold or deep yellow, you need more water.
Keep in mind that your daily water allowance should not be substituted with juice, soda, or anything with artificial sweeteners. Artificial sweeteners have been shown to increase both appetite and sugar cravings, causing weight gain.