We are often asked if tea and coffee contribute to the required daily water intake. If the coffee or tea is caffeine-free, then you can count it as part of your water intake. However, if the tea or coffee is caffeinated, you actually need to drink MORE water to compensate for the dehydrating effect of the caffeine. This means that you need to drink the required 75-100 ounces of water (or half of your body weight in ounces, whichever is greater) PLUS extra water to make up for the caffeine. If you drink 8 oz of a caffeinated beverage, you need to drink an additional 8 ounces of water to compensate.