Staying properly hydrated is essential for health, energy, and performance. Enter your weight and activity level to find out how much water you should drink every day.
Recommended Daily Water Intake
In Milliliters
In Cups (8 oz)
This calculator provides estimates and is for informational purposes only. Consult a healthcare professional for medical advice.
How It Works
Your daily water needs depend primarily on your body weight and how active you are. This calculator uses the widely-recommended baseline of 33 ml per kilogram of body weight, then adjusts for your activity level. Physical activity increases water loss through sweat, so more active individuals need proportionally more hydration.
Factors like climate, altitude, pregnancy, breastfeeding, and illness can further increase your needs. Foods with high water content (fruits, vegetables, soups) also contribute to your total daily water intake. The 8-cup rule is a simplified guideline — your actual needs are individual.
Frequently Asked Questions
Can I drink too much water?
Yes. Drinking an excessive amount of water in a short time can lead to hyponatremia (low blood sodium), though this is rare. Spread your intake throughout the day and listen to your body's thirst signals.
Do coffee and tea count toward water intake?
Yes. While caffeinated beverages have a mild diuretic effect, they still contribute to your overall hydration. Plain water is ideal, but other fluids and water-rich foods also count.
How do I know if I'm drinking enough water?
Pale, straw-colored urine is a good sign of adequate hydration. Dark yellow urine, dry mouth, fatigue, and headaches can all indicate you need more fluids. Thirst is a reliable signal for most people.