Work out a daily water intake estimate from your body weight, activity level and climate. This tool gives a general estimate only — it is not medical advice. If you have a health condition, follow your clinician’s guidance.
General estimate only — not medical advice. Food, illness, pregnancy and medication all change fluid needs.
How to Use
- Enter your body weight and choose kilograms or pounds.
- Pick the activity level closest to a typical day for you.
- Choose your climate, then press Calculate intake.
- Read your estimated litres per day and the matching number of glasses.
Key Features
- Weight-based estimate — starts from 35 ml per kilogram of body weight.
- Activity adjustment — adds fluid for light, moderate and very active days.
- Climate adjustment — warmer weather raises the daily estimate.
- Litres and glasses — see the result both ways at a glance.
- 100% private — runs entirely in your browser; nothing is sent or stored.
FAQs
Is this medical advice?
No. This is a general estimate only. Fluid needs vary with health, medication, pregnancy, heat and exercise — ask a clinician for personal guidance.
How is the estimate worked out?
It starts at 35 ml per kilogram of body weight, then adds extra fluid for your activity level and for a mild or hot climate.
Does food count towards water intake?
Yes — fruit, vegetables, soups and other foods all contribute fluid. This estimate covers total water, not just drinks.
Is my data sent anywhere?
No. The calculation runs entirely in your browser and never transmits or saves your entries.
Related Tools
Try these related tools: Calorie Calculator, BMI Calculator and Sleep Calculator.