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 — Missouri
Daily water target for missouri residents — local climate factored in.
OpenWater Intake — Montana
Daily water target for montana residents — local climate factored in.
OpenWater Intake — Nebraska
Daily water target for nebraska residents — local climate factored in.
OpenWater Intake — Nevada
Daily water target for nevada residents — local climate factored in.
OpenWater Intake — New Hampshire
Daily water target for new hampshire residents — local climate factored in.
OpenWater Intake — New Jersey
Daily water target for new jersey residents — local climate factored in.
OpenWater Intake — New Mexico
Daily water target for new mexico residents — local climate factored in.
OpenWater Intake — New York
Daily water target for new york residents — local climate factored in.
OpenWater Intake — North Carolina
Daily water target for north carolina residents — local climate factored in.
OpenWater Intake — North Dakota
Daily water target for north dakota residents — local climate factored in.
OpenWater Intake — Ohio
Daily water target for ohio residents — local climate factored in.
OpenWater Intake — Oklahoma
Daily water target for oklahoma residents — local climate factored in.
OpenSimple, accurate, personalized
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.