---
title: "How Much Water Do You Really Need? What the Science Actually Says"
slug: how-much-water-do-you-need
category: health
category_label: "Health"
author: "BrainWavePost Staff"
date: 2026-06-06
tags: ["hydration", "water", "health", "nutrition"]
read_time_minutes: 5
canonical_url: https://brainwavepost.com/article/how-much-water-do-you-need
source: BrainWavePost
---

# How Much Water Do You Really Need? What the Science Actually Says

*Health · 2026-06-06 · BrainWavePost Staff · 5 min read*

> A fully sourced summary of daily fluid needs, based on guidance from the U.S. CDC and the National Academies of Sciences, Engineering, and Medicine (NASEM).

> **How this article is sourced** _(info)_
>
> Every recommendation comes from the U.S. Centers for Disease Control and Prevention (CDC) and the National Academies of Sciences, Engineering, and Medicine (NASEM), as summarised by Harvard T.H. Chan School of Public Health. [1][2] This is general health information, not medical advice.

Your body uses water to regulate temperature, lubricate joints, protect sensitive tissues and remove waste. The U.S. CDC notes that getting enough fluids each day is important for normal body function. [1]

## The official intake recommendation

The National Academies of Sciences, Engineering, and Medicine (NASEM) set general 'Adequate Intake' values for total daily water from all beverages and foods: about 3.7 litres (around 125 ounces) for adult men and about 2.7 litres (around 91 ounces) for adult women. Roughly 20% of that typically comes from food. [2]

- **~3.7 L** — total daily water for adult men (NASEM) [2]
- **~2.7 L** — total daily water for adult women (NASEM) [2]
- **~20%** — of daily water usually comes from food (NASEM) [2]

## Plain water is the CDC's recommended default

The CDC recommends plain water as the best everyday choice for staying hydrated for most people, because it has no calories or added sugars. [1]

## Practical CDC tips for drinking more water

- Carry a refillable water bottle and refill it throughout the day. [1]
- Choose water instead of sugar-sweetened beverages. [1]
- Add a slice of lemon, lime or cucumber if you find plain water boring. [1]
- Drink water during and between meals, and when you exercise. [1]

> **Individual needs vary** _(note)_
>
> NASEM stresses that fluid needs depend on age, body size, activity level, climate and overall health. People with certain medical conditions should follow advice from their own clinician. [2]

## References (clickable)

- [1] U.S. Centers for Disease Control and Prevention — Water and Healthier Drinks: https://www.cdc.gov/healthy-weight-growth/water-healthy-drinks/index.html
- [2] Harvard T.H. Chan School of Public Health — The Nutrition Source: Water (summarises the NASEM Dietary Reference Intakes): https://nutritionsource.hsph.harvard.edu/water/

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