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.
Open calculatorExplore the full library
Water Intake for 102 kg
Precise daily target for a 102 kg adult.
OpenWater Intake for 103 kg
Precise daily target for a 103 kg adult.
OpenWater Intake for 104 kg
Precise daily target for a 104 kg adult.
OpenWater Intake for Height 140 cm
Daily hydration target for a 140 cm tall adult.
OpenWater Intake for Height 143 cm
Daily hydration target for a 143 cm tall adult.
OpenWater Intake for Height 146 cm
Daily hydration target for a 146 cm tall adult.
OpenWater Intake for Height 149 cm
Daily hydration target for a 149 cm tall adult.
OpenWater Intake for Height 152 cm
Daily hydration target for a 152 cm tall adult.
OpenWater Intake for Height 155 cm
Daily hydration target for a 155 cm tall adult.
OpenWater Intake for Height 158 cm
Daily hydration target for a 158 cm tall adult.
OpenWater Intake for Height 161 cm
Daily hydration target for a 161 cm tall adult.
OpenWater Intake for Height 164 cm
Daily hydration target for a 164 cm tall adult.
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Pick your calculator
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.