INTERACTIVE TOOL
Hydration estimate calculator
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How to use this tool
- Check that the tool is intended for adults.
- Enter values only to explore the rough calculation.
- Read the warning before treating the number as a personal amount.
Formula or method usedGeneral base = weight × 35 ml, with a moderate adjustment for activity and climate.
Worked example
The number changes with the form assumptions for weight, activity and climate, not with measured personal needs.
Assumptions and limits
Do not use the estimate as a required drinking target. It does not account for medical restrictions.
Frequently asked questions
Should I drink exactly the result?+
No. It is a general reference, not medical advice or a mandatory target.
What happens to my inputs?+
Calculation inputs are processed locally in your browser. Favorites and preferences may be saved on this device. The site may perform separate network requests for live panels; these do not include the values entered into this local calculator. Do not paste secrets into public tools.
How should I check the result?+
Do not use the estimate as a required drinking target. It does not account for medical restrictions.