How does the Water Intake Calculator work?
The base formula is: body weight (kg) × 35 ml. Activity and climate multipliers are then applied. Moderately active people need 10 % more, active people 20 % more, and very active people 30 % more than the baseline. In hot or tropical climates an additional 15 % is added to compensate for sweat losses. The total is divided by 250 ml to get the number of glasses, and divided by 16 waking hours for an hourly sipping guide.