What is the Water Intake Calculator?
Estimate how much water to drink each day from your weight and exercise time.
Enter weight and exercise per day and the Water Intake Calculator returns water per day and in glasses of 250 mL. Results update as you type, and nothing you enter leaves your device.
How it is calculated
Needs rise in hot, humid weather and during illness, pregnancy and breastfeeding. This is a general estimate for adults and not medical advice. Talk to a doctor or dietitian about your own health.
How to use it
- Enter weight in kg.
- Enter exercise per day in minutes.
- Read water per day in the results panel. It updates as you type.
- Change any value to compare scenarios, or use Share to send the result as a link.
Worked example
Common questions
What formula does the Water Intake Calculator use?
It uses: Water (litres) = weight × 0.033 + 0.35 for every 30 minutes of exercise.
What do I need to use the Water Intake Calculator?
You need weight and exercise per day. Sensible starting values are filled in so you can see how it works straight away.
Is the Water Intake Calculator free, and is my data stored?
It is free with no sign-up. The calculation runs in your browser, so the values you enter are not sent to or stored on our server.