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 66 kg
Precise daily target for a 66 kg adult.
OpenWater Intake for 67 kg
Precise daily target for a 67 kg adult.
OpenWater Intake for 68 kg
Precise daily target for a 68 kg adult.
OpenWater Intake for 69 kg
Precise daily target for a 69 kg adult.
OpenWater Intake for 70 kg
Precise daily target for a 70 kg adult.
OpenWater Intake for 71 kg
Precise daily target for a 71 kg adult.
OpenWater Intake for 72 kg
Precise daily target for a 72 kg adult.
OpenWater Intake for 73 kg
Precise daily target for a 73 kg adult.
OpenWater Intake for 74 kg
Precise daily target for a 74 kg adult.
OpenWater Intake for 75 kg
Precise daily target for a 75 kg adult.
OpenWater Intake for 76 kg
Precise daily target for a 76 kg adult.
OpenWater Intake for 77 kg
Precise daily target for a 77 kg 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.