Every hydration calculator, in one place
Personalized water intake targets for humans, kids, athletes, pets, farm animals, plants, and your whole home — backed by research.
Most-used calculators
Adult Daily Water Intake
Personalized daily water target for healthy adults, adjusted for weight, activity, and climate.
Try it nowElderly Water Intake (65+)
Daily hydration target for older adults, with a safe minimum floor and climate adjustments.
Try it nowWater Intake for Weight Loss
Higher-end daily target with pre-meal water boost that supports satiety and weight loss.
Try it nowChild Water Intake (1–13 yrs)
Daily fluid needs for children using the clinical Holliday–Segar rule, adjusted for climate.
Try it nowPregnancy Water Intake
Trimester-based daily water target supporting healthy pregnancy hydration.
Try it nowBreastfeeding Water Intake
Daily fluid target for lactating mothers, scaled to feeding pattern.
Try it nowBrowse by category
Every calculator is grouped so you find the right one in seconds.
Human Calculators
Daily water intake calculators for adults — men, women, elderly, weight-based, and weather-based.
Kids & Pregnancy
Water intake for children, babies, teenagers, pregnancy, and breastfeeding mothers.
Fitness & Sports
Hydration for gym, running, cycling, workouts, and hot-weather exercise.
Medical & Health
Hydration for illness, fever, diabetes, kidney health, and medical conditions.
Outdoor & Travel
Water needs for hiking, camping, flights, and hot-climate travel.
Pet Calculators
Daily water needs for dogs, cats, puppies, kittens, and rabbits.
Farm Animals
Water requirements for horses, cows, goats, sheep, and poultry.
Plants & Garden
Watering calculators for houseplants, lawns, and vegetable gardens.
Home & Utility
Water volume and usage calculators for aquariums, swimming pools, and household water bills.
Popular use cases
Jump straight to what you need.
Get your target in 3 steps
Pick a calculator
Choose from humans, pets, plants, or fitness — whatever fits your need.
Enter your details
Weight, activity, climate, or species. Metric and imperial both supported.
Get a personalized plan
Daily target plus an hourly schedule, adjustments, and a shareable result.
What people are calculating now
Trusted by professionals and families
Every formula is reviewed against published guidelines from EFSA, IOM, WHO, and veterinary nutrition boards. No fluff, no gimmicks — just accurate targets.
- Research-backed formulas with cited sources
- Metric and imperial units on every page
- Free — no sign-up, no paywall, no ads on results
- Mobile-first: works anywhere, loads instantly
"Finally a hydration calc that adjusts for climate. Bookmarked."
"Use this for my dog and my toddler — one site, both answers."
"The hourly schedule is a game-changer during marathon training."
"Accurate, fast, and no annoying pop-ups. Rare these days."
Start with the calculator you need
Free forever. Metric or imperial. Personalized. Pick a category above or browse popular picks.