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 94 lb
Precise daily target for a 94 lb adult.
OpenWater Intake for 95 lb
Precise daily target for a 95 lb adult.
OpenWater Intake for 96 lb
Precise daily target for a 96 lb adult.
OpenWater Intake for 97 lb
Precise daily target for a 97 lb adult.
OpenWater Intake for 98 lb
Precise daily target for a 98 lb adult.
OpenWater Intake for 99 lb
Precise daily target for a 99 lb adult.
OpenWater Intake for a Nurse
Shift-adjusted daily target for a nurse.
OpenWater Intake for a Doctor
Shift-adjusted daily target for a doctor.
OpenWater Intake for a Firefighter
Shift-adjusted daily target for a firefighter.
OpenWater Intake for a Police Officer
Shift-adjusted daily target for a police officer.
OpenWater Intake for a Soldier
Shift-adjusted daily target for a soldier.
OpenWater Intake for a Pilot
Shift-adjusted daily target for a pilot.
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.