How to Use the Workout Hydration Calculator
Fluid loss through sweat varies by intensity, temperature, and individual factors. Losing 2% of body weight in fluids reduces performance, while 5%+ triggers heat illness risk. This calculator estimates your total fluid needs and per-interval intake to keep you safely hydrated.
General guideline: drink 150–200 mL every 15–20 min for light exercise, and 200–300 mL every 15 min for vigorous exercise in hot conditions. For workouts over 60 minutes, replace electrolytes with sports drinks to prevent muscle cramps and optimize absorption.
Frequently Asked Questions
2% body weight loss → 10–20% performance drop. 5%+ loss → dizziness, cramps, heat stroke risk. Vigorous exercise in heat can cause 1–2 L/hr of sweat loss.
Before you feel thirsty — thirst means you are already mildly dehydrated. Aim for 150–250 mL every 15–20 minutes.
Water works for workouts under 60 min. For 60+ minute high-intensity sessions, electrolyte sports drinks help prevent cramps and improve absorption.