Child Hydration Calculator
Daily fluid needs by weight and activity in cups and millilitres, using the standard Holliday-Segar formula and counting fluid from food.
The Holliday-Segar formula puts a 30 kg child at about 1,700 ml of fluid a day — roughly 6.8 cups, or 121 ml per waking hour — including fluid from food.
Child Hydration Calculator
Frequently asked
Is the Child Hydration Calculator free?
Yes. Every tool on AlphaBetaMinds is free, needs no account and has no usage limit.
Does this tool store what I type?
No. It runs entirely in your browser. Your inputs are never sent to our server, and nothing is logged.
How accurate is it?
It uses the McCrindle generation boundaries (Gen Alpha 2010–2024, Gen Beta 2025–2039) and UN World Population Prospects vital rates. Sources and formulas are on our methodology page.
Can I use the result in an article or report?
Yes, with a credit and a link back to this page. See our terms of use for the full licence.
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