Water Intake Calculator
Estimate how much water to drink per day from your bodyweight and daily exercise. Results in liters, ounces and cups. Free, metric and imperial.
| In fluid ounces | 95 oz |
|---|---|
| 8-oz cups | 12 |
Based on about 35 ml per kg of bodyweight plus roughly 350 ml per 30 minutes of exercise. Food and other drinks count too. Needs rise with heat, illness and pregnancy — pale-yellow urine is a good day-to-day guide.
⚕️ This is an educational estimate, not medical advice. Formulas are population averages and can't account for your full health picture — talk to a doctor or registered dietitian before making decisions about diet, weight or training.
How this calculator works
A common rule of thumb is about 35 ml of water per kilogram of bodyweight, plus roughly 350 ml (12 oz) for every 30 minutes of exercise. Food and other drinks count toward the total, so you rarely need to hit it from plain water alone.
Thirst and urine colour are the best everyday guides — aim for pale yellow. Hot weather, illness, pregnancy and breastfeeding all raise your needs above any formula.