Health & fitness
Water Intake Calculator
Estimate a practical daily hydration target from body weight, activity time, and climate.
Interactive calculator
Estimate daily water intake
Use body weight, activity, and climate to set a practical daily hydration target in liters and glasses.
Results
Daily water target
3.33 L
Glasses
13.3
Based on 250 mL glasses
500 mL bottles
6.7
How to use it
- 01Enter body weight in kilograms.
- 02Add the minutes of exercise or heavy activity in a typical day.
- 03Choose the climate level to adjust for temperature and sweating conditions.
Result guide
- The liters result is the clearest planning number for most people.
- Glass and bottle counts help turn the target into something easier to follow during the day.
- Hydration needs can still change with illness, heat exposure, and medical advice.
About this calculator
Water intake tools get repeated use because hydration targets are easy to understand but still benefit from a quick personalized estimate.
The calculator is intentionally simple. It gives a planning baseline, not a medical prescription for every health condition.
Frequently asked questions
Is this target exact for every person?
No. It is a practical estimate, and real needs can vary with diet, weather, medication, and medical conditions.
Why does activity raise the water target?
More movement usually means more sweat loss and a higher need to replace fluids.
Can this be used with hot-weather training?
Yes, but treat it as a baseline rather than a full heat-management protocol.
Method and limitations
This calculator uses the formula and assumptions described on this page. We do not claim independent professional review. Direct references will be listed here when they support a specific rule or data source used by this calculator.
Results are estimates for general information. Verify current rules and assumptions before making financial, tax, or health decisions.
Read our Editorial and Verification Policy →Related calculators
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