Daily Water Intake Calculator
Daily Water Intake Calculator estimates how much water you should drink each day based on your body weight, activity level and climate — shown in liters, ounces and glasses.
Last updated: July 2026
A water intake calculator estimates your daily hydration needs from body weight — about 35 ml per kilogram — then adds extra for exercise and hot climates. Enter your weight in kg or lb, pick your activity level and climate, and read the result in liters, US fluid ounces and 250 ml glasses.
How to use Daily Water Intake Calculator
- Enter your body weight in kg or lb.
- Select your activity level and climate.
- Read your daily target in liters, fluid ounces and glasses.
Frequently asked questions
How is the amount calculated?
A baseline of 35 ml per kg of body weight, plus up to 1 L for exercise and 0.5 L for hot climates.
Does water from food and other drinks count?
Yes — roughly 20% of your fluid intake typically comes from food, so treat the number as a total-fluids guideline.
Is my data stored?
No — the calculation runs entirely in your browser. Nothing is uploaded.
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