How is the result calculated?
The base is 33 ml of water per kilogram of your body weight — the most common formula in general medical sources for estimating a healthy adult's need. Then 350 ml is added per 30 minutes of physical activity, an addition based on weather heat, and an addition for pregnancy or breastfeeding if applicable.
Is this number medically precise?
There's no scientific consensus on one fixed number suitable for everyone — actual need varies by many factors (general health, diet, humidity, climate). This calculator gives you a reasonable estimate to start from, not a substitute for medical consultation for special cases.
Is water from food and other drinks counted?
No, this calculator estimates your need for water and fluids in general. Remember that part of your daily need (estimated at about 20%) usually comes from food (especially vegetables and fruits), so there's no need to necessarily drink the full shown number as plain water alone.
Is drinking more than the recommended amount harmful?
Severe overconsumption of water in a short time can cause hyponatremia (a rare but dangerous condition), especially in athletes who drink very large amounts quickly. Spread your water drinking throughout the day instead of all at once, and consult your doctor if you have a kidney or heart condition requiring fluid restriction.
Why does the addition differ between "hot" and "very hot"?
The higher the heat or humidity, the more fluid the body loses through sweating, increasing the need for replenishment. We chose two approximate levels (hot / very hot) to simplify the choice instead of asking for a precise temperature you might not know.
