Daily Water Intake Calculator

About this calculator

This calculator estimates how much water your body needs each day based on your body weight, how active you are, and the climate you live in — since larger bodies, harder workouts, and hotter or more humid weather all increase fluid loss through sweat and breathing. It converts that estimate into both liters and standard 250 ml glasses so the number is easy to track through the day.

It is useful for athletes and gym-goers planning hydration around training, people living in hot climates or through heatwaves, and anyone simply trying to build a consistent water habit instead of guessing at the old "eight glasses a day" rule, which does not account for individual body size or conditions.