How much water should I drink each day?

Hydration is essential for health. How much water should one drink each day depends on age, body size, activity level, climate, and health status. General guidance from health organizations recommends about 125 fl oz (3.7 L) of total water daily for men and about 91 fl oz (2.7 L) daily for women, including water obtained from foods and beverages. The simple "8x8" rule —eight 8-fl-oz (64 fl oz; 1.9 L) cups— provides an easy starting point but does not fit every person. Clinicians, registered dietitians, and researchers advise individualized targets. During exercise one should add about 16–24 fl oz (0.5–0.7 L) for each hour. Hot or humid conditions increase needs, as do fever, vomiting, diarrhea, pregnancy, and breastfeeding. Signs of adequate hydration include pale yellow urine, regular urination, moist mouth, and normal energy levels. Indicators of dehydration include dark urine, dry mouth, infrequent urination, dizziness, and fatigue. Overhydration can cause hyponatremia, particularly when excessive plain water dilutes blood sodium during prolonged endurance activity. Athletes should balance fluids with electrolytes in long events. Practical tips are carrying a water bottle, drinking at meals, spacing intake through the day, and eating water-rich foods. Beverages such as coffee or tea provide fluid and modest caffeine effects, while alcohol promotes fluid loss. When uncertainty exists, one should consult a primary care clinician or registered dietitian for personalized advice. Evidence-based guidance and individualized planning help optimize hydration and support overall health. Older adults may have blunted thirst cues and should be mindful of scheduled intake. Children have higher fluid needs per body weight and require caregiver attention. Medications such as diuretics alter fluid balance, so medical review is valuable. Monitoring urine color, thirst, and activity context offers simple feedback. Small, frequent sips work better than infrequent large volumes. The goal is adequate hydration without harm.