Formula
Daily ml = weight (kg) × 33 × activity factor × climate factor. Results convert to litres and standard 240 ml cups.
Water Intake Calculator
Estimate daily fluid needs in litres and cups from body weight and activity (33 ml/kg method with activity and climate adjustment).
Your inputs
About this method
When needs increase
Hot weather, fever, diarrhoea, vigorous sport, pregnancy, breastfeeding, and high altitude raise fluid requirements.
Limitations
Does not replace personalised advice for heart failure, dialysis, or fluid-restricted diets. Educational use only.
Frequently asked questions
How much water should I drink daily?
A common starting estimate is about 33 ml of fluid per kilogram of body weight (roughly 30–35 ml/kg), then adjusted upward for exercise, heat, illness, pregnancy, or altitude. Individual needs vary — this tool is a guide, not a prescription.
Does this include all fluids?
Yes in practice: water, tea, coffee, milk, and water-rich foods all contribute. Plain water is still the healthiest default for most people.
Who should not follow a high-fluid plan?
People with heart failure, advanced kidney disease, dialysis, hyponatremia risk, or a clinician-ordered fluid restriction should not increase intake without medical advice.
How does TimeVent calculate water intake?
Daily ml = weight (kg) × 33 × activity factor × climate factor, then clamped between 1.2–6 L and shown as litres, 240 ml cups, and 500 ml bottles.