FREE TOOL
Hydration & Electrolyte Calculator
Your daily water target, plus an honest check on whether a given workout actually calls for an electrolyte supplement.
One safety note: more water is not always better. Overdrinking plain fluid during long events can dilute blood sodium and cause exercise-associated hyponatremia. Drinking to thirst is the safest default. See the full breakdown in our electrolytes guide.
Estimates use a ~35 ml/kg baseline and ACSM fluid-replacement sodium guidance (~500–700 mg/L). Individual sweat rate and sweat-sodium vary widely; treat outputs as a starting point, not a prescription.