Water Intake Calculator

Official guidance from health organizations lands closer to around 3.7 liters of total daily fluids for adult men and 2.7 liters for women, and critically, that figure includes water obtained from food, not just what you drink directly, roughly 20% of typical daily fluid intake actually comes from the food itself rather than a glass.

Exercise changes the math meaningfully too, since sweat carries away both water and electrolytes that need replacing, which is exactly why an athlete training hard needs noticeably more fluid than someone sitting at a desk all day, something a flat daily number was never going to capture accurately.

Enter your body weight, your typical daily exercise duration, and your general climate conditions. The calculator outputs a personalized daily fluid target in ounces or liters, tailored to those specific inputs rather than a generic average.

Worth knowing on the other end of the spectrum: drinking an excessive amount of water in a short window can actually cause hyponatremia, a dangerous dilution of blood sodium levels, so spacing intake evenly through the day matters more than chugging a large amount at once. Your body stats and activity details stay entirely private, calculated locally.