How this calculation works
Estimate a general daily fluid starting point from body weight, activity, and climate. The result is calculated locally in your browser from the visible inputs, and the method below remains available for checking.
Worked example
70 kg with 45 minutes activity starts around 2.75 litres before individual medical needs.
Assumptions and limits
- This is a simple starting estimate, not an official dietary reference intake.
- Food moisture and other beverages contribute to total water intake.
- Pregnancy, illness, medicines, kidney or heart conditions can materially change fluid needs.
Questions people ask
How does the Water Intake Calculator work?
It applies this displayed method: Starting estimate = 35 ml/kg + 400 ml per activity hour, with a 10% climate allowance when selected. Values stay in your browser and are not submitted to a server.
What should I check before using the Water intake result?
This is a simple starting estimate, not an official dietary reference intake. Food moisture and other beverages contribute to total water intake. Pregnancy, illness, medicines, kidney or heart conditions can materially change fluid needs. This is a general adult estimate, not a diagnosis or personalised medical advice. Seek a qualified clinician for health decisions.
Does this Water intake calculator save my information?
No. Calculation inputs are processed on this device. Sharing creates a URL only when you choose the share action.