Water Intake Calculator
Estimate how much water to drink per day in liters, cups, and fluid ounces based on your body weight.
- 8-oz cups
- 10.4 cups
- Fluid ounces
- 83 fl oz
Formula: Water (L) = weight (kg) × ml per kg ÷ 1000
About Water Intake Calculator
Water Intake Calculator is a free online calculator that gives you an instant, accurate result as you type. Estimate how much water to drink per day in liters, cups, and fluid ounces based on your body weight.
The calculation uses the standard formula Water (L) = weight (kg) × ml per kg ÷ 1000 and updates live with every change to the inputs. Everything runs client-side in your browser — fast, private, and free to use as often as you like.
A common guideline is 30–35 ml of water per kilogram of body weight daily, with more needed in hot climates or during exercise.
Results are estimates for educational purposes and not medical advice.
Frequently Asked Questions
Is Water Intake Calculator free to use?
Yes. Water Intake Calculator is completely free, with no sign-up, no downloads, and no usage limits. You can use it as many times as you like on any device with a web browser.
How accurate is this calculator?
The calculator applies the standard formula (Water (L) = weight (kg) × ml per kg ÷ 1000) with full floating-point precision and rounds only the displayed result. For most practical purposes the results are exact.
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