ShulahWater intake calculator
Eight glasses a day fits few people. A better starting point is about 33 ml for every kilogram you weigh, plus more the more you move.
Estimates for healthy adults (Mifflin-St Jeor · Katch-McArdle · Deurenberg · US Navy · Epley). Not medical advice.
How it is calculated
Daily water = weight × 0.033 litres, plus 0.25 to 0.8 L depending on your activity level. It counts everything you drink, not only plain water.
How to read it
Drink through the day rather than all at once, and add more in the heat and on hard training days. Pale yellow urine is the simplest sign you are drinking enough.