Water Intake Calculator
Estimate how much water you should drink each day based on your weight, workouts and climate, then tap to track your glasses with this free water calculator.
Tap a glass each time you drink 8 oz (saved on this device)
How we estimate your water needs
A common starting point is about half an ounce of water per pound of body weight (roughly 33 ml per kg), plus around 12 ounces for every 30 minutes of exercise, and a little more in hot or humid weather. It's a practical daily drinking goal, not a medical prescription.
For context, the U.S. National Academies put adequate total fluid intake at about 15.5 cups a day for men and 11.5 cups for women, and that includes the water in food and other drinks.
Signs you're drinking enough
- Your urine is pale yellow most of the day.
- You rarely feel very thirsty.
- You don't get headaches or fatigue late in the afternoon.
Learn more in how much water you should drink a day, and see how hydration fits into these glow-up tips.
Frequently asked questions
Do coffee and tea count toward water intake?
Yes. Moderate amounts of coffee and tea still hydrate you overall, though plain water is the best everyday choice.
Can you drink too much water?
Yes. Drinking very large amounts quickly, especially during long endurance events, can dangerously lower blood sodium. Sip steadily instead of chugging.
Is the 8 glasses a day rule right?
It's a reasonable reminder but not a scientific rule. Your needs depend on body size, activity, climate and what you eat.
Disclaimer: Results are estimates for healthy adults and are not medical advice.