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 Height 196 cm
Daily hydration target for a 196 cm tall adult.
OpenWater Intake for Height 198 cm
Daily hydration target for a 198 cm tall adult.
OpenWater Intake for Height 199 cm
Daily hydration target for a 199 cm tall adult.
OpenSenior Water Intake at Age 65
Age-adjusted daily hydration target for a 65-year-old senior.
OpenSenior Water Intake at Age 66
Age-adjusted daily hydration target for a 66-year-old senior.
OpenSenior Water Intake at Age 67
Age-adjusted daily hydration target for a 67-year-old senior.
OpenSenior Water Intake at Age 68
Age-adjusted daily hydration target for a 68-year-old senior.
OpenSenior Water Intake at Age 69
Age-adjusted daily hydration target for a 69-year-old senior.
OpenSenior Water Intake at Age 70
Age-adjusted daily hydration target for a 70-year-old senior.
OpenSenior Water Intake at Age 71
Age-adjusted daily hydration target for a 71-year-old senior.
OpenSenior Water Intake at Age 72
Age-adjusted daily hydration target for a 72-year-old senior.
OpenSenior Water Intake at Age 73
Age-adjusted daily hydration target for a 73-year-old senior.
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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.