U.S. Centers for Disease Control and Prevention · reviewed 2026-10-10
What this source supports: Daily fluid needs vary by age, activity, health, and weather; general healthy adults are guided by thirst.
Source limit: This tool gives a general estimate. Ask a clinician about fluid needs during illness, pregnancy, or intense exercise.
These sources support the statements above. They do not show that every person needs this guide. They do not show a specific result.
Limits
This guide compares costs only. It does not judge water quality, and it does not replace a local water report or the filter maker's instructions.
This tool gives a general estimate. Ask a clinician about fluid needs during illness, pregnancy, or intense exercise.
Use current instructions from the responsible organization. This guide is a planning aid, not an official decision or a substitute for qualified advice.
Common questions
What does the App compute?
Compare the yearly cost of the bottles you buy with the yearly cost of a filter or pitcher.
What does the App not do?
This App compares costs from the numbers you enter. It does not judge water quality or replace your local water report or the filter instructions.
Where do the numbers come from?
You enter every number yourself. The sources support the method and the limits. They do not produce a result for your specific case. Keep the original documents next to the sheet you build.
Before you start
Open the linked source page and keep it beside you.
Gather the values the App asks for:
Bottles bought per week.
Price per bottle.
Filter or pitcher cost per year.
Set aside ten quiet minutes; rushed numbers are the main error this guide prevents.
Free Companion App
The App computes the worked example with your own numbers, in your browser.
APP 1
Bottled Water vs Filter Yearly Cost
Compare the yearly cost of the bottles you buy with the yearly cost of a filter or pitcher.
This guide is edited for clarity and checked against the sources it links. It is not a substitute for official instructions or qualified advice. A linked source does not show that every person needs this guide.