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 — Oregon
Daily water target for oregon residents — local climate factored in.
OpenWater Intake — Pennsylvania
Daily water target for pennsylvania residents — local climate factored in.
OpenWater Intake — Rhode Island
Daily water target for rhode island residents — local climate factored in.
OpenWater Intake — South Carolina
Daily water target for south carolina residents — local climate factored in.
OpenWater Intake — South Dakota
Daily water target for south dakota residents — local climate factored in.
OpenWater Intake — Tennessee
Daily water target for tennessee residents — local climate factored in.
OpenWater Intake — Texas
Daily water target for texas residents — local climate factored in.
OpenWater Intake — Utah
Daily water target for utah residents — local climate factored in.
OpenWater Intake — Vermont
Daily water target for vermont residents — local climate factored in.
OpenWater Intake — Virginia
Daily water target for virginia residents — local climate factored in.
OpenWater Intake — Washington
Daily water target for washington residents — local climate factored in.
OpenWater Intake — West Virginia
Daily water target for west virginia 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.