What is a Water Intake Calculator?
A Water Intake Calculator estimates how much water you may need each day from your body weight and daily exercise.
A common guide is about 35 ml per kilogram of body weight, plus extra for exercise. Hot weather, illness, pregnancy and breastfeeding can raise your needs. Food and other drinks also count towards intake.
How to use the Water Intake Calculator
- Enter weight.
- Tap Calculate to see the result.
- Tap Reset to clear the fields and try again.
Who should use it
- People building a daily hydration habit
- Athletes and gym-goers
- Anyone living in a hot climate
Key terms
- Daily water
- Total fluid you may need in a day.
- Exercise minutes
- Time spent on moderate to hard activity.
Frequently asked questions
Do tea and coffee count?
Yes, they add to fluid intake, though water is best.
Can I drink too much water?
Yes. Very large amounts in a short time can be harmful.
Is this medical advice?
No. People with kidney or heart conditions should ask a doctor.
Is my data stored?
No. Everything you enter stays in your browser.
Last updated: 1 November 2026