Daily Water Intake & Hydration Calculator
Proper daily hydration improves cognitive focus, supports digestion, accelerates workout recovery, and boosts physical energy.
How it works
Clinical sports nutrition guidelines recommend consuming ~35ml of water per kg of body weight for baseline organ function, plus an additional 350ml per 30 minutes of cardiovascular exercise to replenish electrolyte-sweat loss.
Formula
Water (ml) = (Weight_kg × 35) + ((Exercise (mins) / 30) × 350)
Calculates baseline hydration at 35 ml per kilogram of body weight, plus an additional 350 ml for every 30 minutes of physical activity.
| Symbol | Variable | Unit | Description |
|---|---|---|---|
| Weight_kg | Body mass in kilograms | kg | |
| Exercise | Daily active physical exercise | mins |
Worked example
70 kg individual with 30 minutes of daily exercise
- Weight:
- 70 kg
- Exercise:
- 30 mins/day
Base requirement = 70 × 35 ml = 2,450 ml (2.45 L). Exercise bonus = (30 / 30) × 350 ml = 350 ml (0.35 L). Total Daily Water = 2.80 Liters (approx. 11 glasses of 250ml).
Limitations
Patients with chronic kidney disease (CKD) or congestive heart failure must follow nephrologist-prescribed fluid restrictions.
Frequently asked questions
Does coffee or tea count toward my daily water intake?
Yes, moderate caffeine beverages contribute to overall fluid intake, though plain pure water, coconut water, and lemon water remain the healthiest hydration sources.
What are the common signs of dehydration?
Early indicators include dark yellow urine, dry mouth, mild headaches, persistent fatigue, and reduced athletic endurance.
Should I drink more water in hot and humid weather?
Yes. In hot climates (like Indian summers) or heavy humidity, sweat rates increase significantly; you should add 500ml to 1,000ml of extra fluids with electrolytes.
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Last reviewed: 2026-08-22.