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 — Mediterranean Plus Diet
Daily fluid target on the mediterranean plus diet.
OpenWater Intake — Dash Plus Diet
Daily fluid target on the dash plus diet.
OpenWater Intake — Ornish Diet
Daily fluid target on the ornish diet.
OpenWater Intake — Engine 2 Diet
Daily fluid target on the engine 2 diet.
OpenWater Intake — Forks Over Knives Diet
Daily fluid target on the forks over knives diet.
OpenWater Intake — Nordic Diet Diet
Daily fluid target on the nordic diet diet.
OpenWater Intake — Japanese Diet Diet
Daily fluid target on the japanese diet diet.
OpenWater Intake — Okinawan Diet Diet
Daily fluid target on the okinawan diet diet.
OpenWater Intake — Biblical Diet Diet
Daily fluid target on the biblical diet diet.
OpenWater Intake — Daniel Fast Diet
Daily fluid target on the daniel fast diet.
OpenWater Intake — Kosher Diet Diet
Daily fluid target on the kosher diet diet.
OpenWater Intake — Halal Diet Diet
Daily fluid target on the halal diet diet.
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Weight, activity, climate, species — takes under 30 seconds.
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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.