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 with Osteoarthritis
Daily fluid target when managing osteoarthritis — safe range and warning signs.
OpenWater Intake with Fibromyalgia
Daily fluid target when managing fibromyalgia — safe range and warning signs.
OpenWater Intake with Chronic Fatigue
Daily fluid target when managing chronic fatigue — safe range and warning signs.
OpenWater Intake with Lyme Disease
Daily fluid target when managing lyme disease — safe range and warning signs.
OpenWater Intake with Epstein Barr
Daily fluid target when managing epstein barr — safe range and warning signs.
OpenWater Intake with Long Covid
Daily fluid target when managing long covid — safe range and warning signs.
OpenWater Intake with Post Covid
Daily fluid target when managing post covid — safe range and warning signs.
OpenWater Intake — India
Localized daily hydration target for india residents with climate factored in.
OpenWater Intake — Pakistan
Localized daily hydration target for pakistan residents with climate factored in.
OpenWater Intake — Bangladesh
Localized daily hydration target for bangladesh residents with climate factored in.
OpenWater Intake — Saudi Arabia
Localized daily hydration target for saudi arabia residents with climate factored in.
OpenWater Intake — Uae
Localized daily hydration target for uae residents with climate factored in.
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.