About WaterIntakeCalc
A free, no-sign-up water intake calculator built on published science — and nothing else.
Our Mission
WaterIntakeCalc exists because the internet's most common hydration advice — “drink eight glasses” — ignores the four things that actually determine your needs: your body weight, your sex, how much you move, and the climate you live in. We built a calculator that asks for exactly those inputs and nothing more, runs entirely in your browser, and never asks you to create an account. Your inputs are stored locally on your device so the tool remembers you on your next visit; nothing is sent to a server, because there is no server.
Our Methodology
Every number on this site traces to a published reference: the baseline of 35 ml per kilogram of body weight simplifies intake guidance from the European Food Safety Authority (EFSA) and the U.S. Institute of Medicine (IOM); the exercise and climate adjustments reflect mainstream sports-nutrition practice. When the science gives a range rather than a point, we say so. When a topic needs a clinician — pregnancy complications, medication interactions, illness — we point you to one instead of playing doctor. We are a hygiene-grade tool for healthy habits, and every page carries a medical disclaimer to keep that boundary honest.
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