How to Use the Electrolyte Drink Need Calculator
Enter your body weight, exercise duration, intensity, and environmental temperature to calculate estimated sweat loss and recommended fluid, sodium, and potassium replacement. The result tells you whether water alone is enough or if a sports drink is recommended.
Water is sufficient for workouts under 60 minutes at moderate intensity. For longer or more intense sessions, especially in heat, electrolyte replacement becomes critical. Sweat contains 500–1,000 mg/L sodium and ~200 mg/L potassium. Drinking only water without replacing electrolytes during prolonged exercise can lead to dangerous hyponatremia.
Frequently Asked Questions
Weigh yourself (without clothes) before and after exercise. Each pound lost equals approximately 15 oz (450 mL) of fluid. Add back whatever you drank during the session for total loss.
Yes — dissolving electrolyte tablets in water is an effective way to control sodium and potassium intake without the added sugars in most sports drinks.
Yes. Thirst lags behind fluid loss. Aim to drink 4–6 oz every 15–20 minutes during moderate exercise, and start hydrating in the 2 hours before a long session.