Sports Hydration Calculator
Calculate fluid and electrolyte needs during exercise based on duration, intensity, and temperature.
Hydration Needs
Exercise hydration depends on sweat rate, which varies with intensity and temperature.
General guidelines:
- Baseline fluid need: 400–800 ml (14–28 oz) per hour of exercise
- Hot conditions (>30C / 86F) can increase needs by 50–100%
- High intensity increases sweat rate by approximately 25–50%
Metric calculation:
Base fluid (ml/hr) = 500 ml × intensity factor × heat factor
Imperial calculation:
Base fluid (oz/hr) = 17 oz × intensity factor × heat factor
Electrolyte needs:
- Sodium: 300–600 mg per hour of exercise
- Potassium: 75–150 mg per hour
- Increase sodium by 50% in hot weather or for heavy sweaters
Intensity factors: Low = 0.8, Moderate = 1.0, High = 1.3, Very High = 1.6
Heat factors: Cool (<15C/59F) = 0.8, Mild (15-24C/59-75F) = 1.0, Warm (25-30C/77-86F) = 1.3, Hot (>30C/86F) = 1.6