Water Intake Calculator
This gives a rough daily water figure from your body weight, using a common rule of thumb. Many things change how much you need, including heat, exercise, illness and diet.
- Free
- Works offline after your first visit
- Saves on this device
- No sign-up
- Updated
How it works
The rule of thumb used here is about 35 millilitres of water for each kilogram of body weight, which is a little over half a fluid ounce per pound. The result is shown in cups or litres.
The figure is a total for drinks, and food also supplies some water. It is a starting point for thinking about intake, not a required target.
Worked example
For a body weight of 160 lb, the rule of thumb gives about 10.7 cup of water a day.
Questions
Does this include food?
The figure is a guide for all fluids. Many people also get some water from food, so the amount you need from drinks alone can be lower.
Should I drink more in heat or when I exercise?
Often, yes. Heat, sweat and exercise raise needs. Pay attention to thirst and to your doctor's advice, especially if you have a health condition.
Is this medical advice?
No. It is a general rule of thumb. Ask a doctor about fluids if you have kidney, heart or other conditions.
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