Water Intake Calculator
Personalised, not the 8-glass myth
65 kg
30 min
—
Total daily water target
—
250 ml glasses
—
1-L bottles
—
Per waking hour (~16h)
—
Cups of tea/coffee OK?
Trust your thirst signal
The classic "8 glasses a day" ignores body size & climate. A 50-kg person in a cool climate needs far less than a 90-kg athlete in Chennai summer. Personalise it.
Related tools
Where the numbers come from
- Base: ~33 ml per kg of body weight (per European Food Safety Authority guidance)
- Exercise: +350 ml per 30 min of moderate-intensity exercise
- Climate: hot/humid adds 300–600 ml via increased sweat
- Pregnancy/breastfeeding: +700 ml baseline
Fluid ≠ water: tea, coffee, fruit, soups and curries count — roughly 20–30% of typical Indian fluid intake comes from food. Coffee is mildly diuretic but net-positive overall.