← All calculators
Nutrition

Water Intake Calculator

Estimate daily water intake from body weight and activity duration.

By Health Fitness Hub Editorial TeamLast reviewed May 6, 2026
Your numbersAgeyrsSexWeightHeightActivity
Baseline hydration estimateWater Intake Calculator
107fl oz/day
Base
2.6 L
Activity add-on
0.5 L
Total
3.2 L
Advanced inputs+

How this works

Uses a practical hydration estimate of 35 ml per kg body weight plus 12 ml for each activity minute.

Medical disclaimer

Educational tool only — not medical advice. Consult a qualified provider.

Frequently asked questions

What does the Water Intake Calculator estimate?+

It estimates daily hydration estimate from body weight and activity minutes. The result is a planning estimate, not a diagnosis or personal medical advice.

How accurate is this water intake result?+

Accuracy depends on the inputs and the limits of the formula. Use the result as a reference point and compare it with real-world outcomes over time.

Can I share my result?+

Yes. Change the inputs, use the copy-link button, and the current values are preserved in the URL for reopening or sharing.

Will my last input be remembered?+

Yes. The calculator saves the latest inputs in this browser so a reload can restore the most recent values.

Should I use this for medical decisions?+

No. These calculators are educational tools. Talk with a qualified clinician before making health, pregnancy, nutrition, or training decisions.

Related tools