OneTool

Water Intake Calculator

A simple heuristic for daily fluid targets — not a prescription.

Units
  • Milliliters

    2,818 ml

  • Liters

    2.82 L

  • Fluid ounces

    95 fl oz

What is this tool?

This calculator uses a common heuristic of about 35 mL of water per kilogram of body weight, adjusted for activity and hot climate. True needs depend on health conditions, environment, and diet (including water in food).

How to use it

  1. Enter body weight and choose activity/climate.
  2. Read suggested daily intake in ml, liters, and fl oz.
  3. Adjust for how you feel and any clinician guidance.