Health · Fact check

Does everyone need to drink eight glasses of water a day?

Rated: Mostly false 2 of 5 on the fact-check scale

Largely no — the evidence mostly does not support this claim.

FalseTrue

The claim

Everyone needs to drink eight glasses of water a day to stay healthy.

What the evidence shows

There is no strong scientific basis for a fixed rule of eight glasses for everyone. Fluid needs vary with body size, activity, climate, and diet, and a substantial share of daily water comes from food and other beverages. Health authorities advise drinking to thirst rather than meeting a single universal quota.

This summary describes a fact-check originally published by Harvard Health Publishing. FactGuard did not conduct this review; we summarize it and link to the original. Read the original fact-check by Harvard Health Publishing →