Daily Fluid Calculator

How this tool works

Enter the size of your glass, your chosen daily target and how much fluid you have already consumed. The result converts the target into millilitres and shows the remaining amount. The NHS describes six to eight cups or glasses of fluid a day as a general guide, not a personal prescription. Other drinks can contribute; needs change with activity, heat and other circumstances. If a clinician has prescribed a fluid restriction or target, use that guidance instead. This tool does not estimate medical requirements from body weight.

How do I get a useful result?

Start by reading the field labels and the method above. Replace the example values with information that matches your own situation, then use the main button to generate the result. Review the units, dates and any assumptions before copying or printing it. If you change an input, run the tool again so the output reflects your latest choices. An example is a starting point for learning the controls, not a recommendation for your circumstances.

Does this page upload my information?

This tool performs its work in your browser. Its input values are not submitted to a server by the calculator. Closing or reloading the page clears unsaved work. Checklist pages offer an explicit browser-save option; that storage belongs to this browser and device and may be cleared by private browsing or browser settings. Downloads, printed pages and copied text contain whatever information you included, so keep them somewhere appropriate.

Can I use it on a phone?

The form and result panels adapt to a smaller screen. Use your device’s normal keyboard to enter values, and review the output before sharing it. The print button opens the browser’s print controls, where available. Printing and saving as PDF depend on your operating system. If a feature is unavailable, try a current browser with JavaScript enabled. Keep a separate copy of anything important; the page is not a cloud backup service.

Method reference: Read the source documentation