Water: How Much Should You Drink?
Water: How Much Should You Drink?
Joy Stepinski, MSN, RN-BC
June 21, 2026
We are advised to drink enough water, but how much is enough? The Centers for Disease Control and Prevention (CDC) states that sufficient water is important for health, but needs vary by age, sex, activity level, pregnancy, and breastfeeding [1]. Climate, heat exposure, physical exertion, and nutrition may also influence hydration status [2].
To maintain water balance, the body needs to compensate for fluid losses, including urine, stool, respiration, and sweat. Daily losses may vary among people depending on their conditions and environment. During intense exercise, individuals may lose more than one liter per hour.
According to the National Academies of Sciences, Engineering, and Medicine [3], Adequate Intake (AI) of total water (from food and beverages) is approximately 3.7 liters per day for men and 2.7 liters for women, aged 19 years and older. About 19% of this total comes from food, and the remainder comes from beverages. Fluid needs increase with physical activity and heat exposure.
Generally, a widely used simplified guideline for daily fluid intake is about 2 liters of water (approximately 8 cups). Individual needs vary according to size, age, activity level, and environmental conditions. Overhydration, while rare, can occur when fluid intake exceeds the kidneys’ ability to excrete excess water. Proper hydration supports many physiological functions, including cognition, bowel regularity, temperature regulation, mood, and kidney function [1].
References:
1. Centers for Disease Control and Prevention. (2024). Fast facts: Data on water consumption. https://www.cdc.gov/nutrition/php/data-research/fast-facts-water-consumption.html
2. Jéquier, E., & Constant, F. (2010). Water as an essential nutrient: The physiological basis of hydration. European Journal of Clinical Nutrition, 64(2), 115-123.
3. Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Panel on Dietary Reference Intakes for Electrolytes, & Water. (2005). Dietary reference intakes for water, potassium, sodium, chloride, and sulfate. National Academies Press.