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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Water Intake at BP 120/80
Hydration when blood pressure is 120/80.
OpenWater Intake at BP 130/85
Hydration when blood pressure is 130/85.
OpenWater Intake at BP 140/90
Hydration when blood pressure is 140/90.
OpenWater Intake at BP 150/95
Hydration when blood pressure is 150/95.
OpenWater Intake at BP 160/100
Hydration when blood pressure is 160/100.
OpenWater Intake at BP 170/105
Hydration when blood pressure is 170/105.
OpenWater Intake at BP 180/110
Hydration when blood pressure is 180/110.
OpenWater Intake for 121 kg
Precise daily target for a 121 kg adult.
OpenWater Intake for 122 kg
Precise daily target for a 122 kg adult.
OpenWater Intake for 123 kg
Precise daily target for a 123 kg adult.
OpenWater Intake for 124 kg
Precise daily target for a 124 kg adult.
OpenWater Intake for 125 kg
Precise daily target for a 125 kg adult.
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Choose the one that matches your situation from the grid above.
Enter a few details
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.