Nutrition Tool

Daily Water Intake Calculator

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Written byPureCalc Editorial Team

Updated: April 27, 2026 • Verified Clinical Formula

Calculate your recommended daily water intake based on your body weight and physical activity level.

Recommended Daily Intake

87oz

In Liters

2.57 L

In Cups

10.9 cups

How Much Water Should You Drink?

Staying properly hydrated is essential for your overall health, digestion, cognitive function, and physical performance. While the common "8 glasses a day" rule is easy to remember, it doesn't account for your unique body size or how much you sweat during exercise.

This calculator uses a widely accepted rule-of-thumb formula to give you a personalized daily water intake goal based on your weight and activity level.

The Hydration Formula

Our calculator uses a two-step formula to determine your baseline and activity-adjusted hydration needs:

  • Base Intake: A general guideline is to drink roughly half your body weight in ounces of water per day. For example, a 150-pound person should aim for 75 ounces of water as a baseline.
  • Exercise Adjustment: Physical activity increases fluid loss through sweat. It's recommended to add 12 ounces of water to your daily total for every 30 minutes of exercise.
Total Ounces = (Weight in lbs / 2) + (12 oz × (Exercise Minutes / 30))

Other Factors to Consider

While this formula provides a solid foundation, you may need even more water if you live in a hot or dry climate, are at high altitude, are pregnant or breastfeeding, or are fighting an illness. Additionally, keep in mind that about 20% of your daily fluid intake comes from moisture-rich foods like fruits and vegetables. Always listen to your body and check the color of your urine (pale yellow is ideal) to gauge your hydration status.