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Water Intake Calculator

Suggested daily water intake from weight and activity.

water-intake-calculator.local
Enter your weight to see a suggested daily intake.

Overview

Estimates how much water you might aim to drink in a day based on your body weight and activity. It is a general guideline to help you set a baseline, not a strict medical target.

How it works

The calculator starts from your body weight, using about 35 mL of water per kilogram as a baseline, since larger bodies generally need more fluid. It then adds for exercise, because activity increases how much you lose through sweat. The result is a daily estimate. Real needs also shift with heat, illness, and diet, and some of your fluid comes from food, so treat the number as a starting point.

How to use it

  1. Choose your units and enter your weight.
  2. Enter how many minutes of exercise you do in a day.
  3. Read your estimated daily water target.
  4. Adjust your intake for hot weather or illness as needed.

Examples

Baseline

At about 35 mL per kg, a 70 kg person gets roughly 2.5 L a day before exercise.

With activity

Adding 30 minutes of exercise brings that to about 2.8 L for the day.

FAQ

Do I need exactly this amount?
No. It is a guideline. Thirst, urine color, and how you feel are practical day-to-day signals, and needs vary between people.
Does coffee or tea count?
Most fluids contribute to hydration, and food provides some too, so the figure is a total fluid guide rather than plain water only.
Can I drink too much?
Drinking very large amounts in a short time can be harmful. Spread intake across the day rather than forcing large volumes at once.
Why does activity change the number?
Exercise increases fluid loss through sweat and breathing, so the calculator adds to your baseline based on the minutes of exercise you enter.
Is my data stored?
No. The estimate is calculated in your browser.

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Paste this snippet to put the tool on your own site. It runs entirely in the visitor's browser, the same as it does here.

<iframe src="https://tooldok.com/embed/water-intake-calculator/" title="Water Intake Calculator by Tooldok" width="100%" height="560" style="border:1px solid #16130d;border-radius:16px;max-width:720px" loading="lazy"></iframe> <p style="font:13px sans-serif"><a href="https://tooldok.com/tools/water-intake-calculator/" target="_blank" rel="noopener">Water Intake Calculator</a> by <a href="https://tooldok.com/" target="_blank" rel="noopener">Tooldok</a></p>