Eight cups of water is a common recommendation for daily hydration. Each cup typically holds about 8 fluid ounces, totaling 64 fluid ounces or approximately 1.89 liters. This amount can help maintain proper bodily functions, including digestion, circulation, and temperature regulation. Drinking enough water is essential for overall health. Factors such as age, activity level, and climate can influence individual hydration needs. While eight cups is a general guideline, some people may require more or less water based on their specific circumstances.