1036 calculators
Human Calculators
Daily water intake calculators for adults — men, women, elderly, weight-based, and weather-based.
Top picks
Most popular in Human Calculators
#1 pick
Adult Daily Water Intake
Personalized daily water target for healthy adults, adjusted for weight, activity, and climate.
Open calculator#2 pick
Elderly Water Intake (65+)
Daily hydration target for older adults, with a safe minimum floor and climate adjustments.
Open calculator#3 pick
Water Intake for Weight Loss
Higher-end daily target with pre-meal water boost that supports satiety and weight loss.
Open calculatorAll calculators
Explore the full library
Page 87 of 87 · 1033 total
How it works
Simple, accurate, personalized
STEP 1
Pick your calculator
Choose the one that matches your situation from the grid above.
STEP 2
Enter a few details
Weight, activity, climate, species — takes under 30 seconds.
STEP 3
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.