Find your daily water intake in seconds
Enter your body weight to get a daily water target in liters, ounces, and cups.
Daily water intake by body weight
Baseline daily water targets at 35 ml per kilogram of body weight, with no extra exercise.
| Body weight | Water (liters) | Water (cups) |
|---|---|---|
| 50 kg | 1.8 L | 7.4 cups |
| 60 kg | 2.1 L | 8.9 cups |
| 70 kg | 2.5 L | 10.4 cups |
| 80 kg | 2.8 L | 11.8 cups |
| 90 kg | 3.2 L | 13.3 cups |
| 100 kg | 3.5 L | 14.8 cups |
| 110 kg | 3.9 L | 16.3 cups |
| 120 kg | 4.2 L | 17.8 cups |
Exercising today? Use the water intake calculator above to add extra fluid for your workout.
About this water intake calculator
This calculator uses a widely cited baseline: roughly 35 milliliters of water per kilogram of body weight per day (about half an ounce per pound). It's a simple starting point, not a precise medical requirement.
Because exercise increases fluid loss through sweat, this calculator adds about 350 ml (roughly 12 oz) for every 30 minutes of exercise on top of your baseline.
Actual needs vary with climate, health conditions, pregnancy, and diet — hot or humid weather in particular can raise your needs well above this baseline. Use this as a starting point, and adjust based on thirst, urine color, and how you feel.
Sample daily water targets
Common body weights, already calculated.
Water intake questions
How the daily water target is calculated.
How much water should I drink a day?
A common baseline is about 35 ml of water per kilogram of body weight (roughly half an ounce per pound) per day. For a 70 kg (154 lb) person, that's about 2.45 liters, or a little over 10 cups.
Does exercise change how much water I need?
Yes. This calculator adds roughly 350 ml (about 12 oz) of water for every 30 minutes of exercise, on top of your baseline needs, to account for extra fluid lost through sweat.
Does climate affect water intake?
Yes — hot or humid weather increases fluid loss through sweat, so you'll likely need more than the baseline estimate on hot days. This calculator gives a starting point, not a fixed target for every condition.
Does all my water intake have to come from drinking water?
No. Food (especially fruits and vegetables) and other beverages also contribute to total fluid intake. The number here is a target for total daily fluids, with plain water being the simplest way to hit it.
Can I drink too much water?
Yes, in rare cases — drinking extremely large amounts of water in a short time can dilute sodium levels in the blood (hyponatremia). This is uncommon with normal daily hydration but worth being aware of during intense endurance exercise.
Is this calculator a substitute for medical advice?
No. It's a general starting point based on body weight and activity. People with kidney, heart, or other medical conditions should follow fluid guidance from their doctor instead.