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 — Illinois
Daily water target for illinois residents — local climate factored in.
OpenWater Intake — Indiana
Daily water target for indiana residents — local climate factored in.
OpenWater Intake — Iowa
Daily water target for iowa residents — local climate factored in.
OpenWater Intake — Kansas
Daily water target for kansas residents — local climate factored in.
OpenWater Intake — Kentucky
Daily water target for kentucky residents — local climate factored in.
OpenWater Intake — Louisiana
Daily water target for louisiana residents — local climate factored in.
OpenWater Intake — Maine
Daily water target for maine residents — local climate factored in.
OpenWater Intake — Maryland
Daily water target for maryland residents — local climate factored in.
OpenWater Intake — Massachusetts
Daily water target for massachusetts residents — local climate factored in.
OpenWater Intake — Michigan
Daily water target for michigan residents — local climate factored in.
OpenWater Intake — Minnesota
Daily water target for minnesota residents — local climate factored in.
OpenWater Intake — Mississippi
Daily water target for mississippi 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.