Water intake calculator
Forget the generic "8 glasses a day" rule. Your hydration needs are as unique as your body weight and the weather.
Equivalent to about 11 cups.
The "8 Glasses" Myth
I genuinely don't know where the "8 glasses" data came from, but it’s mostly marketing fluff. A 110kg athlete training in the desert needs vastly more water than a 50kg person sitting in an air-conditioned office. Hydration is dynamic. Our formula uses a base of **35ml per kg of body weight**, then adds multipliers for sweat loss (exercise) and evaporative loss (climate).
Pro Tip: "Eat" your water. About 20% of your daily hydration actually comes from food. If you eat a lot of cucumber, watermelon, or soup, you might need to drink less than this calculator suggests. The best indicator of hydration isn't this tool—it’s the color of your urine. Aim for pale straw color; if it looks like apple juice, drink up.