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 240 lb
Precise daily target for a 240 lb adult.
OpenWater Intake for 241 lb
Precise daily target for a 241 lb adult.
OpenWater Intake for 242 lb
Precise daily target for a 242 lb adult.
OpenWater Intake for 243 lb
Precise daily target for a 243 lb adult.
OpenWater Intake for 244 lb
Precise daily target for a 244 lb adult.
OpenWater Intake for 245 lb
Precise daily target for a 245 lb adult.
OpenWater Intake for 246 lb
Precise daily target for a 246 lb adult.
OpenWater Intake for 247 lb
Precise daily target for a 247 lb adult.
OpenWater Intake for 248 lb
Precise daily target for a 248 lb adult.
OpenWater Intake for 249 lb
Precise daily target for a 249 lb adult.
OpenWater Intake for 250 lb
Precise daily target for a 250 lb adult.
OpenWater Intake for 251 lb
Precise daily target for a 251 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.