A general guideline is about 35 ml per kg of body weight, adjusted for activity and climate. For a 160-pound (72 kg) person, that is roughly 2.5 liters per day. Active people in warm climates may need 3-4 liters or more.

Yes, coffee and tea contribute to daily hydration despite their mild diuretic effect. Studies show the fluid in caffeinated beverages provides a net positive hydration benefit. However, water remains the ideal primary hydration source.

Yes, overhydration (hyponatremia) is possible but rare in everyday life. It occurs when you drink so much water that sodium levels become dangerously diluted. This is mainly a risk during extreme endurance events. For most people, thirst is a reliable guide.