Daily hydration target based on weight, activity and climate
Water Intake Calculator is a free online browser-based utility designed to daily hydration target based on weight, activity and climate. All computations, processing, and rendering happen completely inside your browser client, ensuring your data is kept secure and private.
This calculator gives a general guideline of about 35 mL per kg of body weight, plus extra for exercise and hot weather. A 70 kg person gets 2,450 mL, or about 2.5 L a day, before adjustments. Needs vary; ask a doctor about personal advice.
The tool adds 350 mL for every 30 minutes of exercise. For a 70 kg person doing 30 minutes daily, the target rises from 2.45 L to 2.8 L. Intense or long sessions, or heavy sweating, may need more than this simple estimate.
Yes. Turning on the hot or humid climate switch adds 0.5 L to your daily target. So 2.8 L becomes 3.3 L. It is a rough allowance, and you may need more if you sweat a lot or spend long periods outdoors.
Yes. The figure is total fluid intake, so it includes water from food, tea, coffee, milk and other drinks. Water from plain drinking is only part of it. The tool also shows the amount in 250 mL glasses and ounces.
Yes, though it is uncommon. Drinking far more than your body needs, especially very quickly, can dilute blood sodium, which is medically serious. Use the figure as a guide, drink to thirst, and check with a doctor if you have kidney, heart or other health conditions.
Yes. Choose lb as the unit and the weight is converted to kg (1 lb = 0.45359237 kg) before the calculation. Weights between 20 and 300 kg (about 45 to 660 lb) are accepted. Results are shown in litres, 250 mL glasses and ounces.
No. Toolskyt operates under a zero-server policy. All calculations, data formatting, and file exports are executed locally on your machine.
No, this tool is 100% free. There are no limits, sign-ups, subscriptions, or hidden charges required.