The general recommendation for daily water intake for adults is about 13 cups (3.7 liters) for men and 9 cups (2.7 liters) for women, including all beverages and water contained in food. These amounts can vary based on factors like age, physical activity, climate, pregnancy, and breastfeeding. The common guideline of eight 8-ounce glasses per day is a simple rule, but actual needs may differ individually. For example, people who exercise more or live in hotter climates usually need more water to stay hydrated.