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 180 lb
Precise daily target for a 180 lb adult.
OpenWater Intake for 181 lb
Precise daily target for a 181 lb adult.
OpenWater Intake for 182 lb
Precise daily target for a 182 lb adult.
OpenWater Intake for 183 lb
Precise daily target for a 183 lb adult.
OpenWater Intake for 184 lb
Precise daily target for a 184 lb adult.
OpenWater Intake for 185 lb
Precise daily target for a 185 lb adult.
OpenWater Intake for 186 lb
Precise daily target for a 186 lb adult.
OpenWater Intake for 187 lb
Precise daily target for a 187 lb adult.
OpenWater Intake for 188 lb
Precise daily target for a 188 lb adult.
OpenWater Intake for 189 lb
Precise daily target for a 189 lb adult.
OpenWater Intake for 190 lb
Precise daily target for a 190 lb adult.
OpenWater Intake for 191 lb
Precise daily target for a 191 lb adult.
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.