Water Intake Reference Calculator
A rough daily water reference from body weight and exercise time.
Results
What this tool does
This applies the common 30–35 ml per kilogram rule of thumb and adds an allowance for exercise. It is a rough orientation, not a medical target: real needs vary with climate, diet, medication and health conditions.
Formula
reference = weight (kg) × ml per kg
Variables
| Symbol | Meaning | Unit |
|---|---|---|
w | Body weight | kg |
r | Value | ml/kg |
ex | Minutes | — |
L | Reference water intake | L/d |
ML | Volume | ml/d |
GL | Quantity | ×250 ml |
Worked example
- Body weight72 kg
- Value33 ml/kg
- Minutes30
- Reference water intake2.74 L/d
- Volume2736 ml/d
- Quantity10.9 ×250 ml
Limitations
- This tool is informational only. It does not diagnose, treat or replace a qualified health professional. Speak to a doctor before making decisions about your health.
- The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.
Frequently asked questions
Is there a real rule for how much water to drink?
Not a precise one. Needs depend on body size, climate, activity, diet and health, and a large share of daily water comes from food rather than drinks. European reference values for total water intake are around 2.0 litres a day for adult women and 2.5 for men, food included. The 30–35 ml per kilogram used here is a common rule of thumb, useful as a rough starting point and nothing more. Thirst and pale urine remain better everyday guides.