What this site is
Water Intake Calculator Free is a small, independent website with a free water intake calculator and a few simple guides. You type your weight, how much you exercise and whether the weather is hot, and the site shows a general daily estimate in ounces, liters, cups and bottles.
The site is run by a small independent team that builds simple, free tools. It is not a medical practice, a clinic or a health brand, and it is not connected to any bottle maker, supplement seller or health organization.
How the numbers work
The estimates use a common rule of thumb and plain arithmetic: about half your body weight in pounds, as ounces, with a little extra for exercise and hot weather. Every calculation runs in your browser, and nothing you type is sent to us. One tested script produces every number you see on the site, so the examples and the tools always agree.
What it is not
We keep the advice general on purpose. This site is for healthy adults 18 and older. It does not give a number for children, and it does not tell anyone how much to drink for a health reason. If you are pregnant or breastfeeding, have kidney or heart conditions, or take medication that affects fluids, please talk to your doctor.
Questions or a result that looks wrong? Use the Contact page. You can also read the medical disclaimer.