Water Intake Calculator

Calculator

Estimated daily fluid need (~35 ml per kg base, adjusted for activity). Includes water from food and other drinks.

Units

Weightkg

Activity level

Result

Estimated Needs

~2.9 L (2940 ml) per day

≈ 12 cups (240 ml) or ~99 fl oz

What Is Water Intake?

Proper hydration supports many bodily functions. A water intake calculator provides a general daily fluid estimate from body weight and activity, but it cannot account for every individual or medical circumstance.

How Much Water Do You Actually Need Daily?

Hydration needs vary with body mass, activity, climate, diet, and health. This water intake calculator uses body weight and activity to produce a general estimate, not a personalized medical recommendation.

Activity Adjustments: If you exercise heavily or work a physical job, you will lose significant water through sweat and need to increase your intake to compensate.
Climate Factors: Living in hot, humid, or dry climates also dramatically increases your daily water requirements.

Does Coffee and Tea Count Towards Daily Fluid Intake?

Yes! While plain water is the best source of hydration, the water contained in food (like fruits and vegetables) and other beverages (like tea and moderate amounts of coffee) also contributes to your total daily fluid intake. Focus on overall fluid consumption to meet your daily hydration needs.

How To Use the Water Intake Calculator

Choose your preferred unit system: metric (kilograms) or imperial (pounds), and enter your current body weight.
Select your daily activity level from the provided options (e.g., sedentary, moderately active, highly active).
Review the estimated daily fluid amount in liters and cups.
Use this recommendation as a guideline to stay properly hydrated, adjusting based on climate, exercise intensity, and individual needs. Use the Example button to load sample values, or Reset to clear all fields.

Daily water intake by body weight

Use this water intake calculator for a general fluid estimate based on body weight and activity level, shown in liters and cups. Climate, exercise, diet, medication, and medical conditions can change the amount a person needs.