Hydration Guides
Learn the basics, then personalize with the calculator.
How Much Water by Weight (kg & lbs)
What major health bodies say about daily water needs, and how to use weight with our calculator.
Hydration for Exercise
What sports bodies advise about drinking during exercise, and how our calculator models training time.
Hydration in Hot vs Cold Climates
How environment influences hydration needs, with references to public‑health guidance.