Quick Answer The "8 glasses a day" rule was never a research finding — it originated from a 1945 recommendation that was widely misquoted. How much water you actually need depends on your body weight, activity level, and climate. Most adults are mildly dehydrated for most of the day without kno...
Source: [Dev.to](https://dev.to/shreyansh_jain/how-much-water-do-you-actually-need-a-science-backed-hydration-guide-48g2)