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
Tinnitus Water Intake
Tinnitus-support hydration.
OpenWater Intake with Gerd Reflux
Daily fluid target when managing gerd reflux — safe range and warning signs.
OpenWater Intake with Ibs Flare
Daily fluid target when managing ibs flare — safe range and warning signs.
OpenWater Intake with Crohns Disease
Daily fluid target when managing crohns disease — safe range and warning signs.
OpenWater Intake with Ulcerative Colitis
Daily fluid target when managing ulcerative colitis — safe range and warning signs.
OpenWater Intake with Celiac Disease
Daily fluid target when managing celiac disease — safe range and warning signs.
OpenWater Intake with Fatty Liver
Daily fluid target when managing fatty liver — safe range and warning signs.
OpenWater Intake with Cirrhosis Mild
Daily fluid target when managing cirrhosis mild — safe range and warning signs.
OpenWater Intake with Gallstones
Daily fluid target when managing gallstones — safe range and warning signs.
OpenWater Intake with Pancreatitis Recovery
Daily fluid target when managing pancreatitis recovery — safe range and warning signs.
OpenWater Intake with Hypertension Stage 1
Daily fluid target when managing hypertension stage 1 — safe range and warning signs.
OpenWater Intake with Hypertension Stage 2
Daily fluid target when managing hypertension stage 2 — safe range and warning signs.
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.