Looking for a daily water intake calculator litres by weight? This free tool gives you daily water intake in litres and glasses by weight and activity. Just enter your numbers and press Calculate — results are instant.
A common guide is about 33 millilitres of water per kilogram of body weight a day, plus extra when you are active or it is hot. This calculator uses that guide: your weight times 33 ml, plus an activity addition, gives your daily intake in litres — and divides it into 250 ml glasses so it is easy to picture. Food also provides some water, and your real need changes with weather, exercise and health, so treat the result as a target, not a prescription.
Example: Body weight 70 kg · Activity: moderate (daily walk / exercise)
Daily Water Intake: 2.81 litres
It is a common guide used by health authorities as a starting point for adults. It is simple and works for most people, but it is a guide, not a medical rule.
Yes. Sweating loses water fast, so hot weather, hard training and physical work all raise your need. That is why the calculator adds an amount for activity.
Yes, though it is rare. Drinking far more than you need in a short time can dilute the salts in your blood. Thirst is a good guide for most healthy people — drink when you are thirsty and a little more when you are active.