Human Calculators
Daily water intake calculators for adults — men, women, elderly, weight-based, and weather-based.
Most popular in Human Calculators
Adult Daily Water Intake
Personalized daily water target for healthy adults, adjusted for weight, activity, and climate.
Open calculatorElderly Water Intake (65+)
Daily hydration target for older adults, with a safe minimum floor and climate adjustments.
Open calculatorWater Intake for Weight Loss
Higher-end daily target with pre-meal water boost that supports satiety and weight loss.
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Student Water Intake (Exam Day)
Focus-friendly hydration for study and exam days.
OpenDesk Worker Water Intake
Sedentary office hydration target.
OpenStanding Desk Water Intake
Adjusted hydration for standing-desk users.
OpenHumid Climate Water Intake
Higher target for tropical / humid weather.
OpenDry / Arid Climate Water Intake
Arid climate hydration adjustment.
OpenHigh Altitude Water Intake
Hydration boost for altitudes above 2500m.
OpenDesert Travel Water Intake
Daily water for desert environments.
OpenWinter Water Intake
Indoor-heating adjusted winter hydration.
OpenWomen's Daily Water Intake
EFSA female reference — adjusted for weight and activity.
OpenMen's Daily Water Intake
EFSA male reference — adjusted for weight and activity.
OpenWater Intake for 50 kg Person
Personalized daily water target for a 50 kg adult.
OpenWater Intake for 70 kg Person
Personalized daily water target for a 70 kg adult.
OpenSimple, accurate, personalized
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Choose the one that matches your situation from the grid above.
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Weight, activity, climate, species — takes under 30 seconds.
Get your target
A research-backed daily target plus an hourly schedule.
Learn the science behind human calculators
Read our in-depth guides for research-backed context on every calculator here.