Health authorities have historically suggested at least 8 glasses, 8 fluid ounces each , of water per day (64 fluid ounces. This common misconception is not supported by scientific research. Water is of major importance to all living things; in some organisms, up to 90 percent of their body weight comes from water. Up to 60 percent of the human body is water, the brain is composed of 70 percent water, and the lungs are nearly 90 percent water. So, drink up for better health and efficiency! Thanks for visiting and please come back often!